electrical engineering

BASIC THEORY OF TRANSFORMERS

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<span style="background-color: red; font-size: large;">INTRODUCTION </span></div>
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The invention of the power transformer in the latter part of the nineteenth century made possible the development of the modern constant voltage AC supply system, with power stations often located many miles from the centers of electrical load. Before that, in the early days, the supplies were DC systems with generation, of necessity close to the point of loading.<br />
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The amount of auxiliary plant needing electrical supply in a large power station requires five or possibly six different voltage levels, requiring 60 or more transformers to provide the interconnections.<br />
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The transformer interconnects and transfers power between systems at different voltages. It does this at very high efficiency, at 99% or higher.<br />
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Transformers in power stations are generally three phase and double wound, i.e. they have electrically separate primary and secondary windings<br />
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<span style="font-size: large;"><span style="background-color: yellow; color: red;">BASIC THEORY OF TRANSFORMERS</span></span></div>
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<span style="color: black; font-size: large;"><span style="font-size: small;"><span style="background-color: white;"> In figure 1, an ac generator connected to circuit 1 , referred to as PRIMARY, transfers energy to the magnetic circuit, which in turn transfers this energy to circuit 2, referred to as SECONDARY. The flux in the core  </span></span></span><span style="color: black;"> φ</span><span style="font-size: large;"><span style="color: black; font-size: small;"><span style="background-color: white;">M  is common to both circuits, and is responsible for this transfer of energy.</span></span></span><br />
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<img alt="http://www7.0zz0.com/2010/12/25/13/455207520.png" src="http://www7.0zz0.com/2010/12/25/13/455207520.png" /><span style="font-size: large;"><span style="color: black; font-size: small;"><span style="background-color: white;"> </span></span></span></div>
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<span style="background-color: orange; color: red;">Fig. 1.1. Ideal transformer</span></div>
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In an ideal transformer, there are no losses in the core and the windings have no resistance or leakage reactance.<br />
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Consequently, the voltage V1 applied at the primary terminals will be used to circulate the primary current I1 against the opposing emf induced by the main flux. This INDUCED EMF e1 can be calculated by the following equation:<br />
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e1 = N1 x change in flux <br />
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or e1  =  N1  x change in flux  /  change in t    ( 1 )<br />
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where N1 is the number of primary turns.<br />
Similarly, the secondary winding is linked by the same flux as the primary winding and will have an emf e2 induced in it, <br />
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e2 = N2 x change in flux   ( 2 )<br />
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where N2 is the number of secondary turns.<br />
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In the above e1 and e2 are instantaneous values of induced voltage. However it is usual and more convenient to use rms ( root mean square) values. It can be shown that, as a general formula <br />
E  =  4.44 N <span style="color: black;">φ</span>M f     ( 3 )<br />
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where    </div>
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E = rms induced voltage<br />
N = number of turns<br />
<span style="color: black;">φ</span>M = rms value of flux<br />
f = system frequency ( 60 cps)<br />
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In an ideal transformers, the losses which are normally small are ignored, and then<br />
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V1 / V2  =  N1 / N2 = I2 / I1      ( 4 )<br />
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This important relationship must be clearly understood and memorized.<br />
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<span style="background-color: yellow; color: red; font-size: small;">The operation of the transformer can be summarized as follows:</span></div>
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1.    When an alternating voltage V1 is applied to a primary coil of N1 turns linking a suitable iron core as shown in figure 1. A magnetizing reactive current flows in the coil, establishing flux <span style="color: black;">φ</span>M in the core (and small additional fluxes elsewhere, neglected for a first consideration).<br />
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2.    The flux <span style="color: black;">φ</span>M, is such that it induces in the primary coil an emf E1, by self induction to counter the applied voltage V1 and establish electrical balance. If a secondary coil of N2 turns is linked by the same flux, then by mutual induction, an emf E2, is developed in this coil. If a load is connected to the secondary coil, a current I2 will flow in the secondary circuit under the influence of induced voltage E2. This induced voltage E2 appears across the secondary terminals as V2.<br />
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<span class="post-date updated">السبت، 25 ديسمبر، 2010 </span>
     <span class="author vcard">  <span class="fn">justaneng</span></span>

BASIC THEORY OF TRANSFORMERS

INTRODUCTION The invention of the power transformer in the latter part of the nineteenth century made possible the development of the modern constant voltage AC supply system, with power stations of…

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25 Dec 2010

TROUBLESHOOTING OF TRANSFORMER

<div style="text-align: center;"><span style="color: white;">TROUBLE SHOOTING OF TRANSFORMER</span></div><table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; margin-left: auto; margin-right: auto; text-align: left;"><tbody>
<tr style="height: 29.3pt; page-break-inside: avoid;">   <td colspan="4" style="-moz-background-clip: border; -moz-background-inline-policy: continuous; -moz-background-origin: padding; background: rgb(217, 217, 217) none repeat scroll 0% 0%; border-color: windowtext; border-style: double double solid; border-width: 4.5pt 4.5pt 1pt; height: 29.3pt; padding: 0cm; width: 392.2pt;" width="523"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 15.15pt; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">TROUBLE   SHOOTING OF TRANSFORMER</span></b></div></td>  </tr>
<tr style="height: 22.1pt; page-break-inside: avoid;">   <td style="-moz-background-clip: border; -moz-background-inline-policy: continuous; -moz-background-origin: padding; background: rgb(217, 217, 217) none repeat scroll 0% 0%; border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 3pt 4.5pt; height: 22.1pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 8.15pt; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">NO.</span></b></div></td>   <td style="-moz-background-clip: border; -moz-background-inline-policy: continuous; -moz-background-origin: padding; background: rgb(217, 217, 217) none repeat scroll 0% 0%; border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 3pt medium; height: 22.1pt; padding: 0cm; width: 89.85pt;" width="120"><h5>TROUBLES</h5></td>   <td style="-moz-background-clip: border; -moz-background-inline-policy: continuous; -moz-background-origin: padding; background: rgb(217, 217, 217) none repeat scroll 0% 0%; border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 3pt medium; height: 22.1pt; padding: 0cm; width: 110pt;" width="147"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 6.35pt; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">CAUSE</span></b></div></td>   <td style="-moz-background-clip: border; -moz-background-inline-policy: continuous; -moz-background-origin: padding; background: rgb(217, 217, 217) none repeat scroll 0% 0%; border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 3pt medium; height: 22.1pt; padding: 0cm; width: 158.8pt;" width="212"><div align="center" class="MsoNormal" style="direction: ltr; margin-right: 14pt; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">ACTION</span></b></div></td>  </tr>
<tr style="height: 160.05pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext; border-style: none solid none double; border-width: medium 1pt medium 4.5pt; height: 160.05pt; padding: 0cm; width: 33.55pt;" width="45"><div class="MsoNormal" style="direction: ltr; margin-left: 17.1pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">1</span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none solid none none; border-width: medium 1pt medium medium; height: 160.05pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">Stop of transformer</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">(Except OLTC)</span></div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none solid none none; border-width: medium 1pt medium medium; height: 160.05pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; margin-left: 7pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">Internal fault of</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 7pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">main tank</span></div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none double none none; border-width: medium 4.5pt medium medium; height: 160.05pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoNormal" style="direction: ltr; margin: 0cm 14pt 0.0001pt 18.75pt; text-align: left; text-indent: -12pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">(1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Check on relay  </span></div><div class="MsoNormal" style="direction: ltr; margin: 0cm 14pt 0.0001pt 18.75pt; text-align: left; text-indent: -12pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">     </span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">operation.</span></div><div class="MsoNormal" style="direction: ltr; line-height: 150%; margin: 0cm 14pt 0.0001pt 18.75pt; text-align: left; text-indent: -12pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt; line-height: 150%;">(2)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt; line-height: 150%;"> Electrical tests</span></div><div class="MsoBodyTextIndent3" style="margin: 0cm 36.75pt 0.0001pt; text-indent: -30pt;"><b>-1</b>    Measurement of insulation resistance</div><div class="MsoBodyTextIndent3" style="margin: 0cm 36.75pt 0.0001pt; text-indent: -30pt;"><br />
</div><div class="MsoNormal" style="direction: ltr; margin-left: 36.75pt; text-align: left; text-indent: -30pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">-2</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Measurement of winding resistance</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 36.75pt; text-align: left; text-indent: -30pt; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; margin-left: 36pt; text-align: left; text-indent: -29.25pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">-3</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Measurement of voltage ratio.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 36pt; text-align: left; text-indent: -29.25pt; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; margin-left: 36.75pt; text-align: left; text-indent: -30pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">-4</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Measurement of exciting current</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 4.15pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">(3)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Gas analysis of    </span></div><div class="MsoNormal" style="direction: ltr; margin-left: 4.15pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">     </span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">transformer</span></div></td>  </tr>
<tr style="height: 154.65pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid double double; border-width: medium 1pt 4.5pt 4.5pt; height: 154.65pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 17.1pt; text-align: center; text-indent: -19.25pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">1-1</span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; height: 154.65pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">Operation of differntial   relay and buchholz relay or pressure relief device operate simultaneously</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; height: 154.65pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> (1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Internal fault</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double double none; border-width: medium 4.5pt 4.5pt medium; height: 154.65pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoNormal" style="direction: ltr; margin-left: 7.55pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">Action shall be same as   internal</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 7.55pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">fault procedures.</span></div></td>  </tr>
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<tr style="height: 50.25pt; page-break-inside: avoid;">   <td style="border-color: windowtext windowtext -moz-use-text-color; border-style: double solid none double; border-width: 4.5pt 1pt medium 4.5pt; height: 50.25pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 17.1pt; text-align: center; text-indent: -17.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">1-2</span></b></div></td>   <td style="border-color: windowtext windowtext -moz-use-text-color -moz-use-text-color; border-style: double solid none none; border-width: 4.5pt 1pt medium medium; height: 50.25pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">Operation of buchholz relay   and pressure relief device</span></div></td>   <td style="border-color: windowtext windowtext -moz-use-text-color -moz-use-text-color; border-style: double solid none none; border-width: 4.5pt 1pt medium medium; height: 50.25pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> <b>(2)</b> Internal fault</span></div></td>   <td style="border-color: windowtext windowtext -moz-use-text-color -moz-use-text-color; border-style: double double none none; border-width: 4.5pt 4.5pt medium medium; height: 50.25pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoNormal" style="direction: ltr; margin-left: 7.55pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">Action shall be same as   internal</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 7.55pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">fault procedures.</span></div></td>  </tr>
<tr style="height: 67pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext; border-style: none solid none double; border-width: medium 1pt medium 4.5pt; height: 67pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 17.1pt; text-align: center; text-indent: -17.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">1-3</span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none solid none none; border-width: medium 1pt medium medium; height: 67pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">simultaneously</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">Operation of</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">differential</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">relay only</span></div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none solid none none; border-width: medium 1pt medium medium; height: 67pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> (1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Internal fault</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> (2)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Inrush current        </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">      at time of       </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">      energyization</span></div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none double none none; border-width: medium 4.5pt medium medium; height: 67pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoBodyTextIndent3" style="margin-left: 6.75pt; text-indent: 0cm;"><b>(1)</b>   Action shall be same  </div><div class="MsoBodyTextIndent3" style="margin-left: 6.75pt; text-indent: 0cm;"><b>     </b>as internal fault </div><div class="MsoBodyTextIndent3" style="margin-left: 6.75pt; text-indent: 0cm;">     procedures.</div><div class="MsoBodyTextIndent3"><br />
</div><div class="MsoNormal" style="direction: ltr; line-height: 150%; margin-left: 7.55pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt; line-height: 150%;">(2)-1</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt; line-height: 150%;"> Setting   values of </span></div><div class="MsoNormal" style="direction: ltr; line-height: 150%; margin-left: 7.55pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt; line-height: 150%;">        </span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt; line-height: 150%;">relays.</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">  <b>(2)-2</b> Value of inrush   </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">          current.</span></div></td>  </tr>
<tr style="height: 67pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; height: 67pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 17.1pt; text-align: center; text-indent: -17.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">1-4</span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 67pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">Operation of buchholz relay (trip) only</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 67pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> (1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Internal fault</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> (2)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Faulty   </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">      operation</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; height: 67pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoBodyTextIndent3"><b>(1)</b> Action shall be same as internal fault   procedures.</div><div class="MsoBodyTextIndent3"><br />
</div><div class="MsoNormal" style="direction: ltr; line-height: 150%; margin-left: 7.55pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt; line-height: 150%;">(2)-1</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt; line-height: 150%;"> Check   wiring.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 7pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;">(2)-2</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"> Check contacts.</span></div></td>  </tr>
<tr style="height: 67pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; height: 67pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 17.1pt; text-align: center; text-indent: -17.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">1-5</span></b><b><span style="font-family: Arial; font-size: 11pt;"></span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 67pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">Operation of pressure device </span><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.3pt;">Only</span><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"></span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 67pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> (1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Interal fault</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.3pt;"> (2)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.3pt;"> </span><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">Faulty Operation</span><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.9pt;"></span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; height: 67pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoNormal" style="direction: ltr; margin-left: 21.85pt; text-align: left; text-indent: -18pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(1)</span></b><span style="font-family: Arial; font-size: 11pt;"> Action   shall be same as internal fault procedures.</span></div><div align="left" class="MsoBodyText2" style="margin: 0cm 4.05pt 0.0001pt 7pt; text-align: left;"><b>(2)-1</b>   Check wiring.</div><div class="MsoBodyTextIndent3"><b><span style="letter-spacing: 0.4pt;">(2)-2</span></b><span style="letter-spacing: 0.4pt;"> Check contacts.</span></div></td>  </tr>
<tr style="height: 67pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; height: 67pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 17.1pt; text-align: center; text-indent: -17.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">1-6</span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 67pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">Winding temp.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">indicator or</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">oil temp. indicator</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 67pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> (1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Internal fault</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> (2)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Faulty operation</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> (3)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Stop of cooling   </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">      fan.</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; height: 67pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoNormal" style="direction: ltr; margin-left: 21.85pt; text-align: left; text-indent: -18pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">(1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Action shall be same as internal fault procedures.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 11.2pt; text-align: left; text-indent: -7.35pt; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> <b>(2)-1</b> Check wiring</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 33.85pt; text-align: left; text-indent: -30pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> (2)-2</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Sudden   variation of oil  temperature.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 21.85pt; text-align: left; text-indent: -18pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">(3)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">    Check cooling fan.</span><span style="font-family: Arial; font-size: 11pt;"></span></div></td>  </tr>
<tr style="height: 67pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; height: 67pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">2</span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 67pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">Operation of</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">buchholz: relay</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">(alarm) only</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 67pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> (1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Internal fault</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> (2)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Trapped air or   </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">      evoluation of   </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">      dissolved gases</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; height: 67pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> <b>(1)</b> Action shall be same   as    </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">      internal fault procedures.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 27.6pt; text-align: left; text-indent: -27pt; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">  <b>(2) -1</b> Analysis of gas   </span></div><div class="MsoNormal" style="direction: ltr; margin-left: 27.6pt; text-align: left; text-indent: -27pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">           </span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">accumulated</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 48.25pt; text-align: left; text-indent: -14.4pt; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">  in Buchholz Relay.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 21.85pt; text-align: left; text-indent: -18pt; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> <b>(2)-2</b> Sudden variation of oil    </span></div><div class="MsoNormal" style="direction: ltr; margin-left: 21.85pt; text-align: left; text-indent: -18pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">          </span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">temperature.</span></div></td>  </tr>
<tr style="height: 67pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid double double; border-width: medium 1pt 4.5pt 4.5pt; height: 67pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">3</span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; height: 67pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">Operation of relays such as   overcurrent relay, ground relay, arrestor etc.</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; height: 67pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; margin-left: 9pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">(1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Internal fault</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 9pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">(2)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> External faults such as short- circuit</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 9pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">In the system</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 7pt; text-align: left; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double double none; border-width: medium 4.5pt 4.5pt medium; height: 67pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">(1)</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Action shall be same as   </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">       internal fault   procedures.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 11.2pt; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; margin-left: 11.2pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">(2) -1</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Check any sign of </span></div><div class="MsoNormal" style="direction: ltr; margin-left: 11.2pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">         </span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">Heavy   current</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">            circulation in the</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">            windings.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 11.2pt; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">(2) -2</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Check any sign of</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 43pt; text-align: left; text-indent: -34.4pt; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">          on-load tap changer interrupting heavy   short-circuit current.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 45.6pt; text-align: left; text-indent: -34.4pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">(2) -3</span></b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;"> Short-circuit current value, its duration time.</span></div></td>  </tr>
</tbody></table><br />
<br />
<br />
<div style="text-align: center;"></div><table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; margin-left: auto; margin-right: auto; text-align: left;"><tbody>
<tr style="height: 32.55pt; page-break-inside: avoid;">   <td style="border-color: windowtext; border-style: double solid solid double; border-width: 4.5pt 1pt 1pt 4.5pt; height: 32.55pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">4</span></b></div></td>   <td style="border-color: windowtext windowtext windowtext -moz-use-text-color; border-style: double solid solid none; border-width: 4.5pt 1pt 1pt medium; height: 32.55pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-left: 8.85pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">Abnormality is found in   recording devices</span></div></td>   <td style="border-color: windowtext windowtext windowtext -moz-use-text-color; border-style: double solid solid none; border-width: 4.5pt 1pt 1pt medium; height: 32.55pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; margin-left: 27pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">- ditto -</span></div></td>   <td style="border-color: windowtext windowtext windowtext -moz-use-text-color; border-style: double double solid none; border-width: 4.5pt 4.5pt 1pt medium; height: 32.55pt; padding: 0cm; width: 158.8pt;" width="212"><div align="center" class="MsoNormal" style="direction: ltr; margin-left: 11.2pt; text-align: center; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">- ditto -</span></div></td>  </tr>
<tr style="height: 44.15pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext; border-style: none solid none double; border-width: medium 1pt medium 4.5pt; height: 44.15pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none solid none none; border-width: medium 1pt medium medium; height: 44.15pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">         High   </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;"> temperature</span><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">   rise</span></div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none solid none none; border-width: medium 1pt medium medium; height: 44.15pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 14.4pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Period   required to Reach the maximum temperature and ambient temperature</span><span style="font-family: Arial; font-size: 11pt; letter-spacing: 0.4pt;">, Load </span><span style="font-family: Arial; font-size: 11pt;">factor or type of   load. Connection diagram of bank and internal connection tap voltage.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 8.75pt; text-align: left; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none double none none; border-width: medium 4.5pt medium medium; height: 44.15pt; padding: 0cm; width: 158.8pt;" width="212"><div class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: left; text-indent: -9pt; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">    If the oil temperature is about 80`C   over, the<sub> </sub>transformer must not be operated continuously.</span></div></td>  </tr>
<tr style="height: 269.4pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext; border-style: none solid none double; border-width: medium 1pt medium 4.5pt; height: 269.4pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none solid none none; border-width: medium 1pt medium medium; height: 269.4pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-left: 5.35pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Burned coil</span></div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none solid none none; border-width: medium 1pt medium medium; height: 269.4pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Date and   time of burning.       Installation   site. Perod of use(immediately after operation period). Cause of failure:</span></div><div class="MsoNormal" style="direction: ltr; margin-top: 10.8pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">   Overload</span></div><div class="MsoNormal" style="direction: ltr; margin-top: 10.8pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">    Lighting</span></div><div class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Short   circuiting</span></div><div class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">(internal or   external)</span></div><div class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Others</span></div><div class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: left; text-indent: -9pt; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Existence   or absense of copper powder. Operation of protective devices (primary and   secondary)</span></div><div class="MsoNormal" style="direction: ltr; margin-top: 10.8pt; text-align: left; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext -moz-use-text-color -moz-use-text-color; border-style: none double none none; border-width: medium 4.5pt medium medium; height: 269.4pt; padding: 0cm; width: 158.8pt;" width="212"><div align="center" class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: center; text-indent: -9pt; unicode-bidi: embed;"><br />
</div></td>  </tr>
<tr style="height: 44.15pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid double double; border-width: medium 1pt 4.5pt 4.5pt; height: 44.15pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; height: 44.15pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-top: 7.2pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">  Local heating</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 5.35pt; text-align: left; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; height: 44.15pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; margin-left: 9pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Heated point. Load   factor or type of load. Smoke.     Discoloration</span><span style="font-family: Arial; font-size: 11pt;">.</span></div><div class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: left; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double double none; border-width: medium 4.5pt 4.5pt medium; height: 44.15pt; padding: 0cm; width: 158.8pt;" width="212"><div align="center" class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: center; text-indent: -9pt; unicode-bidi: embed;"><br />
</div></td>  </tr>
</tbody></table><br />
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<table border="0" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; margin-left: auto; margin-right: auto; text-align: left;"><tbody>
<tr style="height: 44.15pt; page-break-inside: avoid;">   <td style="border-color: windowtext windowtext -moz-use-text-color; border-style: double solid none double; border-width: 4.5pt 1pt medium 4.5pt; height: 44.15pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: windowtext windowtext -moz-use-text-color -moz-use-text-color; border-style: double solid none none; border-width: 4.5pt 1pt medium medium; height: 44.15pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-top: 7.2pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Insulation   resistance</span></div><div class="MsoNormal" style="direction: ltr; margin-top: 7.2pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">failure</span></div></td>   <td style="border-color: windowtext windowtext -moz-use-text-color -moz-use-text-color; border-style: double solid none none; border-width: 4.5pt 1pt medium medium; height: 44.15pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; text-align: justify; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Insulation   resistance:     </span></div><div class="MsoNormal" style="direction: ltr; text-align: justify; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">   </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">High voltage winding to low voltage   winding and tank. Low voltage winding to high voltage winding and tank.</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">High voltage winding to low voltage   winding. Temperature and humidity at which mea surement is made.</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Installation site (indoors or   outdoors). History of the transformer.</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Dielectric strangth of the insulation   oil.</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: windowtext windowtext -moz-use-text-color -moz-use-text-color; border-style: double double none none; border-width: 4.5pt 4.5pt medium medium; height: 44.15pt; padding: 0cm; width: 158.8pt;" width="212"><div align="center" class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: center; text-indent: -9pt; unicode-bidi: embed;"><br />
</div></td>  </tr>
<tr style="height: 44.15pt; page-break-inside: avoid;">   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid double double; border-width: medium 1pt 4.5pt 4.5pt; height: 44.15pt; padding: 0cm; width: 33.55pt;" width="45"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; height: 44.15pt; padding: 0cm; width: 89.85pt;" width="120"><div class="MsoNormal" style="direction: ltr; margin-top: 7.2pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Noise</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; height: 44.15pt; padding: 0cm; width: 110pt;" width="147"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Operating conditions</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">(overload, normal)</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double double none; border-width: medium 4.5pt 4.5pt medium; height: 44.15pt; padding: 0cm; width: 158.8pt;" width="212"><div align="center" class="MsoNormal" style="direction: ltr; margin: 10.8pt 0cm 0.0001pt 9pt; text-align: center; text-indent: -9pt; unicode-bidi: embed;"><br />
</div></td></tr>
</tbody></table>

TROUBLESHOOTING OF TRANSFORMER

TROUBLE SHOOTING OF TRANSFORMER TROUBLE SHOOTING OF TRANSFORMER NO. TROUBLES CAUSE ACTION 1 Stop of transformer(Except OLTC) Internal fault ofmain tank (1) Check on relay …

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25 Dec 2010

TROUBLESHOOTING OF O.L.T.C

<div style="text-align: center;"><span style="color: white;">TROUBLE SHOOTING OF O.L.T.C</span></div><div></div><table border="1" cellpadding="0" cellspacing="0" class="MsoTableGrid" style="border-collapse: collapse; border: medium none; margin-left: auto; margin-right: auto; text-align: left;"><tbody>
<tr>   <td rowspan="4" style="border-color: windowtext; border-style: double solid solid double; border-width: 4.5pt 1pt 1pt 4.5pt; padding: 0cm 5.4pt; width: 27.85pt;" valign="top" width="37"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
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</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">       <b>5</b></span></div></td>   <td rowspan="4" style="border-color: windowtext windowtext windowtext -moz-use-text-color; border-style: double solid solid none; border-width: 4.5pt 1pt 1pt medium; padding: 0cm 5.4pt; width: 101.15pt;" valign="top" width="135"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
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</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Malfunction in transformer ( in   case of OLTC)</span></div></td>   <td rowspan="4" style="border-color: windowtext windowtext windowtext -moz-use-text-color; border-style: double solid solid none; border-width: 4.5pt 1pt 1pt medium; padding: 0cm 5.4pt; width: 117.15pt;" valign="top" width="156"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Driverter switch fault</span></div></td>   <td style="border-color: windowtext windowtext windowtext -moz-use-text-color; border-style: double double solid none; border-width: 4.5pt 4.5pt 1pt medium; padding: 0cm 5.4pt; width: 171pt;" valign="top" width="228"><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(1)<span style="font-family: "Times New Roman"; font-size-adjust: none; font-size: 7pt; font-stretch: normal; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal;">                 </span></span></b><span dir="LTR"><span style="font-family: Arial; font-size: 11pt;">Electrical tests.</span></span></div><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">a.<span style="font-family: "Times New Roman"; font-size-adjust: none; font-size: 7pt; font-stretch: normal; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal;">               </span></span></b><span dir="LTR"><span style="font-family: Arial; font-size: 11pt;">Measurement of insulation resistance.</span></span></div><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">b.<span style="font-family: "Times New Roman"; font-size-adjust: none; font-size: 7pt; font-stretch: normal; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal;">              </span></span></b><span dir="LTR"><span style="font-family: Arial; font-size: 11pt;">Measurement of voltage rat.</span></span></div><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">c.<span style="font-family: "Times New Roman"; font-size-adjust: none; font-size: 7pt; font-stretch: normal; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal;">               </span></span></b><span dir="LTR"><span style="font-family: Arial; font-size: 11pt;">Measurement of exciting current.</span></span></div><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><br />
</div></td>  </tr>
<tr>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; padding: 0cm 5.4pt; width: 171pt;" valign="top" width="228"><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(2)</span></b><span style="font-family: Arial; font-size: 11pt;"> Gas analysis of OLTC oil.</span></div></td>  </tr>
<tr>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; padding: 0cm 5.4pt; width: 171pt;" valign="top" width="228"><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(3)</span></b><span style="font-family: Arial; font-size: 11pt;"> Check any operation of relay</span></div></td>  </tr>
<tr>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; padding: 0cm 5.4pt; width: 171pt;" valign="top" width="228"><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(4)</span></b><span style="font-family: Arial; font-size: 11pt;"> Check any external short      circuit.</span></div></td>  </tr>
<tr style="height: 28.4pt;">   <td rowspan="2" style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; height: 28.4pt; padding: 0cm 5.4pt; width: 27.85pt;" valign="top" width="37"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><br />
</div><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><br />
</div><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">5-1</span></b></div></td>   <td rowspan="2" style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 28.4pt; padding: 0cm 5.4pt; width: 101.15pt;" valign="top" width="135"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Operation of Buchholz relay   simulationeously.</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; height: 28.4pt; padding: 0cm 5.4pt; width: 117.15pt;" valign="top" width="156"><div class="MsoNormal" style="direction: ltr; margin-left: 21.6pt; text-align: left; text-indent: -21.6pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(1)</span></b><span style="font-family: Arial; font-size: 11pt;"> Diverter switch fult.</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><br />
</div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; height: 28.4pt; padding: 0cm 5.4pt; width: 171pt;" valign="top" width="228"><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(1)</span></b><span style="font-family: Arial; font-size: 11pt;"> Action shall be same as diverter switch fault.</span></div></td>  </tr>
<tr>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; padding: 0cm 5.4pt; width: 117.15pt;" valign="top" width="156"><div class="MsoNormal" style="direction: ltr; margin-left: 21.6pt; text-align: left; text-indent: -21.6pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(2)</span></b><span style="font-family: Arial; font-size: 11pt;"> Faulty operation of relay</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; padding: 0cm 5.4pt; width: 171pt;" valign="top" width="228"><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(2)-1</span></b><span style="font-family: Arial; font-size: 11pt;"> Check wiring.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(2)-2</span></b><span style="font-family: Arial; font-size: 11pt;"> Check contacts.</span></div></td>  </tr>
<tr>   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; padding: 0cm 5.4pt; width: 27.85pt;" valign="top" width="37"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">5-2</span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; padding: 0cm 5.4pt; width: 101.15pt;" valign="top" width="135"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Relay (No. 48) actuation for   incomplete tap changing.</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid solid none; border-width: medium 1pt 1pt medium; padding: 0cm 5.4pt; width: 117.15pt;" valign="top" width="156"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">     Diverter switch.</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double solid none; border-width: medium 4.5pt 1pt medium; padding: 0cm 5.4pt; width: 171pt;" valign="top" width="228"><div class="MsoNormal" style="direction: ltr; margin-left: 1.1pt; text-align: left; text-indent: -1.1pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(1)</span></b><span style="font-family: Arial; font-size: 11pt;"> Action shall be same as diverter switch fault.</span></div></td>  </tr>
<tr>   <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid double double; border-width: medium 1pt 4.5pt 4.5pt; padding: 0cm 5.4pt; width: 27.85pt;" valign="top" width="37"><div align="center" class="MsoNormal" style="direction: ltr; text-align: center; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">6</span></b></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; padding: 0cm 5.4pt; width: 101.15pt;" valign="top" width="135"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">Improper stopping positions due to   incomplete tap changing or out-of stop in tap position</span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none solid double none; border-width: medium 1pt 4.5pt medium; padding: 0cm 5.4pt; width: 117.15pt;" valign="top" width="156"><div class="MsoNormal" style="direction: ltr; margin-left: 17.3pt; text-align: left; text-indent: -18pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(1)<span style="font-family: "Times New Roman"; font-size-adjust: none; font-size: 7pt; font-stretch: normal; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal;">   </span></span></b><span dir="LTR"><span style="font-family: Arial; font-size: 11pt;">Driving motor    </span></span></div><div class="MsoNormal" style="direction: ltr; margin-left: -0.7pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">      does not operate</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 17.3pt; text-align: left; text-indent: -18pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(2)<span style="font-family: "Times New Roman"; font-size-adjust: none; font-size: 7pt; font-stretch: normal; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal;">   </span></span></b><span dir="LTR"><span style="font-family: Arial; font-size: 11pt;">Driving motor  </span></span></div><div class="MsoNormal" style="direction: ltr; margin-left: -0.7pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">      operare but  </span></div><div class="MsoNormal" style="direction: ltr; margin-left: -0.7pt; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">      incomplete tap-changing take place.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 21.6pt; text-align: left; text-indent: -21.6pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(1)<span style="font-family: "Times New Roman"; font-size-adjust: none; font-size: 7pt; font-stretch: normal; font-style: normal; font-variant: normal; font-weight: normal; line-height: normal;">      </span></span></b><span dir="LTR"><span style="font-family: Arial; font-size: 11pt;">Excessive operating   torque</span></span></div></td>   <td style="border-color: -moz-use-text-color windowtext windowtext -moz-use-text-color; border-style: none double double none; border-width: medium 4.5pt 4.5pt medium; padding: 0cm 5.4pt; width: 171pt;" valign="top" width="228"><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(1)-1</span></b><span style="font-family: Arial; font-size: 11pt;"> Check any operation of  </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">         circuit breaker, any   </span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><span style="font-family: Arial; font-size: 11pt;">         improper voltage.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 28.3pt; text-align: left; text-indent: -30.6pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;"> (1)-2</span></b><span style="font-family: Arial; font-size: 11pt;"> Check motor, magnet brake pilot   switches relays (No. 4866).</span></div><div class="MsoNormal" style="direction: ltr; text-align: left; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(1)-3</span></b><span style="font-family: Arial; font-size: 11pt;"> Check control circuit.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 30.6pt; text-align: left; text-indent: -30.6pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(2)-1</span></b><span style="font-family: Arial; font-size: 11pt;"> Check any slipping of magnetic brake.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 30.6pt; text-align: left; text-indent: -29.3pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(2)-2</span></b><span style="font-family: Arial; font-size: 11pt;"> Check contact positions close and open.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 30.6pt; text-align: left; text-indent: -30.6pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(2)-3</span></b><span style="font-family: Arial; font-size: 11pt;"> Check time setting value of relay No. 48T.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 30.6pt; text-align: left; text-indent: -30.6pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(3)-1</span></b><span style="font-family: Arial; font-size: 11pt;"> Tap position where excessive torque ocurrs.</span></div><div class="MsoNormal" style="direction: ltr; margin-left: 30.6pt; text-align: left; text-indent: -30.6pt; unicode-bidi: embed;"><b><span style="font-family: Arial; font-size: 11pt;">(3)-2</span></b><span style="font-family: Arial; font-size: 11pt;"> Check torque value by manual operation at driving mechanism and its   number manual operation.</span></div></td></tr>
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TROUBLESHOOTING OF O.L.T.C

TROUBLE SHOOTING OF O.L.T.C 5 Malfunction in transformer ( in case of OLTC) Driverter switch fault (1) Electrical tests.a. Measurement of insulation …

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