BEARING AND LUBRICATION PART 2

<div style="background-color: white; color: red; text-align: center;"><span style="font-size: large;"><a href="http://hayatei.blogspot.com/2010/12/bearing-and-lubrication.html">BEARING AND LUBRICATION PART 1 </a></span></div><div style="background-color: white; color: red; text-align: center;"><br /> </div><div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: large;">Lubrication</span></div><br /> <br /> <div style="text-align: justify;"><span style="font-size: large;"><span style="font-size: small;"> Grease is widely used in lubricating the anti friction bearing. The standard grease recommended by Mitsubishi Electric is SHELL DRUM R grease which is superior in lubrication, lubricating life, water and heat resistivity. The anti-friction bearing is supplied with required amount of grease at the time of motor assembly in the shop, but grease is to be again added at the time of the trial run at the site or after the motor has been left un-operated for more than two months.</span></span></div><span style="font-size: large;"><br /> </span><br /> <div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: large;">Caution</span></div><br /> <div style="text-align: justify;"><span style="font-size: large;"><span style="font-size: small;">Only SHELL DRUM R is to be used. If different grease is mixed, a chemical change occurs and the lubricating capacity is greatly decreased </span></span></div><br /> <div style="text-align: center;"><span style="font-size: large;"><span style="background-color: yellow; color: red;"> Supply Of Grease  </span></span></div><br /> <div style="text-align: justify;"><span style="font-size: large;"><span style="font-size: small;">The lubricating capability of the originally-supplied grease decreases as the motor is operated for a certain period of time. Therefore, more grease should be supplied depending on the bearing size and motor revolution after the motor has been operated for a certain period of time. Plate indicating the supply amount of grease fitted at the motor frame. </span></span></div><div style="text-align: justify;"><br /> </div><div style="text-align: justify;"><span style="font-size: small;">Grease is to be supplied by means of a grease gun, and grease nipple is to be cleaned before using the gun. (Fig. 1-4)<br /> be sure to supply grease while the motor is in operation</span></div><div style="text-align: justify;"><br /> </div><div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: large;">Caution</span></div><div style="text-align: justify;"><span style="font-size: small;"></span></div><div style="text-align: justify;"><span style="font-size: small;"></span></div><div style="text-align: justify;"><span style="font-size: small;"></span></div><div style="text-align: justify;"><span style="font-size: small;"></span></div><div style="text-align: justify;"><span style="font-size: small;"></span></div><div style="text-align: justify;"><span style="font-size: small;"><br />  </span></div><div style="text-align: center;"><span style="font-size: large;"><span style="background-color: yellow; color: red;"></span></span></div><div style="text-align: justify;"><span style="font-size: large;"><span style="font-size: small;">A care should be taken not to supply an excessive amount of grease as this may cause the overheating of the bearing </span></span></div><div style="text-align: justify;"><br /> </div><div style="text-align: center;"></div><div style="text-align: center;"></div><div style="text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/bearing-and-lubrication-part-2.html"><img alt="http://img102.herosh.com/2010/12/21/974725694.png" src="http://img102.herosh.com/2010/12/21/974725694.png" /></a> </div><div style="text-align: center;"></div><div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: large;">Fig. 1-4 Supply of Grease</span></div><div style="background-color: white; color: red; text-align: center;"></div><div style="text-align: center;"></div><div style="text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/bearing-and-lubrication-part-2.html"><img alt="http://img103.herosh.com/2010/12/21/923283009.png" src="http://img103.herosh.com/2010/12/21/923283009.png" /></a></div><div style="background-color: white; color: red; text-align: center;"></div><div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: large;">Fig. 1-5 Removal Of Bearing</span></div><div style="background-color: white; color: red; text-align: center;"></div><div style="background-color: white; color: red; text-align: center;"></div>

BEARING AND LUBRICATION PART 2

BEARING AND LUBRICATION PART 1 Lubrication  Grease is widely used in lubricating the anti friction bearing. The standard grease recommend...

more information

BEARING AND LUBRICATION

<div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: medium;"><span style="font-family: Arial;">Construction</span></span></div><br /> <div style="text-align: justify;"><span style="font-size: medium;"><span style="color: black; font-family: Arial;"><span style="font-size: x-small;">The anti-friction bearing is used according to loads; and SHELL DRUM R grease is applied, since it is superior lubricant and resist deterioration. The typical bearing construction is shown in Fig. 1-3 </span></span></span></div><br /> <div style="text-align: center;"><span style="font-size: medium;"><span style="color: black; font-family: Arial;"> </span></span><a href="http://hayatei.blogspot.com/2010/12/bearing-and-lubrication.html"><img alt="http://img105.herosh.com/2010/12/21/806900401.png" src="http://img105.herosh.com/2010/12/21/806900401.png" /></a></div><br /> <div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: medium;">Fig.1-3 Bearing Construction</span></div><br /> <table border="1" cellpadding="0" cellspacing="0" class="MsoNormalTable" style="border-collapse: collapse; border: medium none; margin-left: 62.1pt;"><tbody> <tr style="height: 22pt;"> <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: windowtext; border-style: double solid solid double; border-width: 4.5pt 1pt 2.25pt 4.5pt; height: 22pt; padding: 0cm; width: 49.5pt;" width="66"><div align="center" class="MsoNormal" style="text-align: center;"><b><span style="font-family: Arial; font-size: 11pt;">Item 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: windowtext windowtext windowtext -moz-use-text-color; border-style: double solid solid none; border-width: 4.5pt 1pt 2.25pt medium; height: 22pt; padding: 0cm; width: 103pt;" width="137"><div align="center" class="MsoNormal" style="text-align: center;"><b><span style="font-family: Arial; font-size: 11pt;">Item</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: windowtext windowtext windowtext -moz-use-text-color; border-style: double solid solid none; border-width: 4.5pt 1pt 2.25pt medium; height: 22pt; padding: 0cm; width: 45.8pt;" width="61"><div align="center" class="MsoNormal" style="text-align: center;"><b><span style="font-family: Arial; font-size: 11pt;">Item 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: windowtext windowtext windowtext -moz-use-text-color; border-style: double double solid none; border-width: 4.5pt 4.5pt 2.25pt medium; height: 22pt; padding: 0cm; width: 159.4pt;" width="213"><div align="center" class="MsoNormal" style="text-align: center;"><b><span style="font-family: Arial; font-size: 11pt;">Item</span></b></div></td> </tr> <tr style="height: 16.55pt;"> <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; height: 16.55pt; padding: 0cm; width: 49.5pt;" width="66"><div align="center" class="MsoNormal" style="text-align: center;"><span style="font-family: Arial; font-size: 11pt;">1</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: 16.55pt; padding: 0cm; width: 103pt;" width="137"><div class="MsoNormal" style="text-indent: 3.55pt;"><span style="font-family: Arial; font-size: 11pt;">Grease nipple</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: 16.55pt; padding: 0cm; width: 45.8pt;" width="61"><div align="center" class="MsoNormal" style="text-align: center;"><span style="font-family: Arial; font-size: 11pt;">6</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: 16.55pt; padding: 0cm; width: 159.4pt;" width="213"><div class="MsoNormal" style="text-indent: 5.75pt;"><span style="font-family: Arial; font-size: 11pt;">Locking washer</span></div></td> </tr> <tr style="height: 17.3pt;"> <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; height: 17.3pt; padding: 0cm; width: 49.5pt;" width="66"><div align="center" class="MsoNormal" style="text-align: center;"><span style="font-family: Arial; font-size: 11pt;">2</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: 17.3pt; padding: 0cm; width: 103pt;" width="137"><div class="MsoNormal" style="text-indent: 3.55pt;"><span style="font-family: Arial; font-size: 11pt;">Bracket cover ,</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: 17.3pt; padding: 0cm; width: 45.8pt;" width="61"><div align="center" class="MsoNormal" style="text-align: center;"><span style="font-family: Arial; font-size: 11pt;">7</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: 17.3pt; padding: 0cm; width: 159.4pt;" width="213"><div class="MsoNormal" style="text-indent: 5.75pt;"><span style="font-family: Arial; font-size: 11pt;">Shaft</span></div></td> </tr> <tr style="height: 18pt;"> <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; height: 18pt; padding: 0cm; width: 49.5pt;" width="66"><div align="center" class="MsoNormal" style="text-align: center;"><span style="font-family: Arial; font-size: 11pt;">3</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: 18pt; padding: 0cm; width: 103pt;" width="137"><div class="MsoNormal" style="text-indent: 3.55pt;"><span style="font-family: Arial; font-size: 11pt;">Grease pipe</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: 18pt; padding: 0cm; width: 45.8pt;" width="61"><div align="center" class="MsoNormal" style="text-align: center;"><span style="font-family: Arial; font-size: 11pt;">8</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: 18pt; padding: 0cm; width: 159.4pt;" width="213"><div class="MsoNormal" style="text-indent: 5.75pt;"><span style="font-family: Arial; font-size: 11pt;">Anti-friction bearing</span></div></td> </tr> <tr style="height: 17.75pt;"> <td style="border-color: -moz-use-text-color windowtext windowtext; border-style: none solid solid double; border-width: medium 1pt 1pt 4.5pt; height: 17.75pt; padding: 0cm; width: 49.5pt;" width="66"><div align="center" class="MsoNormal" style="text-align: center;"><span style="font-family: Arial; font-size: 11pt;">4</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: 17.75pt; padding: 0cm; width: 103pt;" width="137"><div class="MsoNormal" style="text-indent: 3.55pt;"><span style="font-family: Arial; font-size: 11pt;">Bracket</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: 17.75pt; padding: 0cm; width: 45.8pt;" width="61"><div align="center" class="MsoNormal" style="text-align: center;"><span style="font-family: Arial; font-size: 11pt;">9</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: 17.75pt; padding: 0cm; width: 159.4pt;" width="213"><div class="MsoNormal" style="text-indent: 5.75pt;"><span style="font-family: Arial; font-size: 11pt;">Bearing cover</span></div></td> </tr> <tr style="height: 21.25pt;"> <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: 21.25pt; padding: 0cm; width: 49.5pt;" width="66"><div align="center" class="MsoNormal" style="text-align: center;"><span style="font-family: Arial; font-size: 11pt;">5</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: 21.25pt; padding: 0cm; width: 103pt;" width="137"><div class="MsoNormal" style="text-indent: 3.55pt;"><span style="font-family: Arial; font-size: 11pt;">Grease runner</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: 21.25pt; padding: 0cm; width: 45.8pt;" width="61"><div align="center" class="MsoNormal" style="text-align: center;"><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: 21.25pt; padding: 0cm; width: 159.4pt;" width="213"><div align="center" class="MsoNormal" style="text-align: center;"><br /> </div></td> </tr> </tbody></table><br /> <br /> <br /> <div style="background-color: yellow; color: red; text-align: center;"><span style="font-size: medium;">Maintenance</span></div><div style="text-align: center;"><br /> </div><div style="text-align: center;"><br /> </div><div style="text-align: justify;">Any abnormal condition of the bearing during motor oper¬ation results in temperature rise, abnormal noise, etc. The knowledge of the motor's normal operating condition serves to make correct judgment as to whether the motor is in normal operating condition or not.<br /> <br /> In case, SHELL DRUM R grease superior in heat resistance is used, the temperature rise is limited to 55 degrees on the surface, when the reference ambient temperature is 40º C.The high temperature of the lubricant (grease) results in the increase in the deterioration of the lubricant, and so usually, keep the temperature not to exceed 95º C, or 105ºC at the highest.<br /> <br /> It is difficult to describe noise, but in some case, a friction sound of the retainer can be heard like a keen metallic sound. This occurs due to the inadequate supply of grease, and so the noise goes out as soon as more grease is supplied. And similar friction sound of the retainer can be heard when the motor is restarted after long stand-by (especially in winter).<br /> <br /> The noise nearly dies out after a small amount of grease is supplied or after the motor is operated for 20 minutes or so.</div>

BEARING AND LUBRICATION

Construction The anti-friction bearing is used according to loads; and SHELL DRUM R grease is applied, since it is superior lubricant and r...

more information

electrical calculation software review

<div style="text-align: justify;"><div style="text-align: justify;">Following discussions on the forum, you will find in this article the comparison I started to create between 4 electrical calculation software, used for the design and calculation of electrical installation, based on my own experience. I would be glad to get complementary information and opinions from other users of such electrical software.</div><div style="text-align: justify;"><br /> </div><div style="text-align: justify;"><br /> </div><a href="http://hayatei.blogspot.com/2010/12/electrical-calculation-software-review.html"><img alt="" class="size-full wp-image-2545 alignnone" height="124" src="http://engineering.electrical-equipment.org/wp-content/uploads/2010/10/logos-softs-V2.jpg" title="logos-softs-V2" width="491" /></a><br /> <div style="text-align: justify;"></div><br /> </div> The comparison presents the following <a href="http://hayatei.blogspot.com/">electrical calculation software</a>:<br /> <br /> <a href="http://www.legrand.fr/professionnels/logiciel-xl-pro2-calcul_1540.html" target="_blank"><b>- XLpro² Calcul</b></a> software from Legrand 1.3<br /> <a href="http://www.automation.siemens.com/mcms/electrical-design-software/en/service-support/simaris-software/Pages/default.aspx" target="_blank"><b>- Simaris Design</b></a> 5.0 from Siemens<br /> <a href="http://www.soft.schneider-electric.com/myecodialL.htm" target="_blank"><b>- MyEcodial L</b></a> 3.4 from Schneider Electric<br /> <a href="http://www.alpi.fr/index.php/scr=21c/" target="_blank"><b>- Caneco BT</b></a> 5.3 from ALPI (software editor)<br /> <div style="text-align: justify;"><br /> </div><div style="text-align: justify;"><br /> </div><div style="text-align: justify;">I believe my criteria are self-explanatory, but tell me if some are not and I will clarify.<br /> <br /> please add your own opinions and complements in comments, such as:</div><div style="text-align: justify;"><br /> • other criteria of importance for you<br /> • other electrical calculation software you are using, and your evaluation on my criteria<br /> <br /> In particular, I heard about DocWin which I do not know.<br /> <br /> Based on your feedbacks, I will update my comparison and re-publish it<br /> <br /> Laurent </div><div style="text-align: justify;"><br /> </div><table border="1" cellpadding="0" cellspacing="0" style="width: 550px;"><tbody> <tr></tr> <tr><td valign="bottom" width="114"><br /> </td> <td valign="bottom" width="142"><a href="http://www.legrand.fr/professionnels/logiciel-xl-pro2-calcul_1540.html" target="_blank"><b>XLpro² Calcul 1.3.03</b></a></td> <td valign="bottom" width="142"><a href="http://www.automation.siemens.com/mcms/electrical-design-software/en/service-support/simaris-software/Pages/default.aspx" target="_blank"><b>Simaris Design 5.0</b></a></td> <td valign="bottom" width="142"><a href="http://www.soft.schneider-electric.com/myecodialL.htm" target="_blank"><b>MyEcodial L 3.4</b></a></td> <td valign="bottom" width="132"><a href="http://www.alpi.fr/index.php/scr=21c/" target="_blank"><b>Caneco BT 5.3</b></a></td> </tr> <tr> <td valign="bottom" width="114"><b>MV protection</b></td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="132">No</td> </tr> <tr> <td valign="bottom" width="114"><b>// transfo</b></td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="132">Yes</td> </tr> <tr> <td valign="bottom" width="114"><b>LV genset</b></td> <td valign="bottom" width="142">Yes (only on MLVS)</td> <td valign="bottom" width="142">Yes at any place in the network</td> <td valign="bottom" width="142">Yes (only on MLVS)</td> <td valign="bottom" width="132">Yes (only on MLVS)</td> </tr> <tr> <td valign="bottom" width="114"><b>Switchboard coupling</b></td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="132">No</td> </tr> <tr> <td valign="bottom" width="114"><b>UPS</b></td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="132">Yes</td> </tr> <tr> <td valign="bottom" width="114"><b>Operating mode</b></td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="132">No</td> </tr> <tr> <td valign="bottom" width="114"><b>Power factor correction</b></td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="132">Yes but no choice of the capacitor bank</td> </tr> <tr> <td valign="bottom" width="114"><b>Fuse</b></td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="132">Yes</td> </tr> <tr> <td valign="bottom" width="114"><b>Motor starter</b></td> <td valign="bottom" width="142">No</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="132">Yes</td> </tr> <tr> <td valign="bottom" width="114"><b>Protection diagram</b></td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">Yes</td> <td valign="bottom" width="142">Yes (with curve setting)</td> <td valign="bottom" width="132">Yes</td> </tr> <tr> <td rowspan="2" valign="bottom" width="114"><b>Standard compliance</b></td> <td valign="bottom" width="142">IEC 60364</td> <td rowspan="2" valign="bottom" width="142">IEC 60364</td> <td valign="bottom" width="142">IEC 60364</td> <td valign="bottom" width="132">IEC 60364</td> </tr> <tr> <td valign="bottom" width="142">NF C15-100</td> <td valign="bottom" width="142">NF C15-100</td> <td valign="bottom" width="132">NF C15-100</td> </tr> <tr> <td valign="bottom" width="114"><b>User friendlyness</b></td> <td valign="bottom" width="142">Clear and single diagram user friendly</td> <td valign="bottom" width="142">Clear and single diagram user friendly</td> <td valign="bottom" width="142">Sometime confusing</td> <td valign="bottom" width="132">Too much information to set, confusing, single line diagram not easy to use</td> </tr> <tr> <td valign="bottom" width="114"><b>Report completion</b></td> <td valign="bottom" width="142">basic</td> <td valign="bottom" width="142">basic</td> <td valign="bottom" width="142">basic</td> <td valign="bottom" width="132">Very detailed</td> </tr> <tr> <td valign="bottom" width="114"><b>Export</b></td> <td valign="bottom" width="142">To XLpro²</td> <td valign="bottom" width="142">??</td> <td valign="bottom" width="142">To Rapsody</td> <td valign="bottom" width="132">Caneco Implant, Office Elec.</td> </tr> <tr> <td valign="bottom" width="114"><b>Switchgear database</b></td> <td valign="bottom" width="142">Legrand</td> <td valign="bottom" width="142">Siemens</td> <td valign="bottom" width="142">Schneider Electric</td> <td valign="bottom" width="132">Multi-manufacturer</td> </tr> <tr> <td valign="bottom" width="114"><b>Price</b></td> <td valign="bottom" width="142">Free</td> <td valign="bottom" width="142">Free</td> <td valign="bottom" width="142">Free</td> <td valign="bottom" width="132">~ 1000 €</td></tr> </tbody></table>

electrical calculation software review

Following discussions on the forum, you will find in this article the comparison I started to create between 4 electrical calculation softwa...

more information

Prevention Of Megger Reduction and Drying

<div style="text-align: justify;"><h3 class="post-title entry-title"><span style="font-size: large;"><span style="color: #351c75;"><span style="font-weight: normal;">This post is the 4th part of </span></span></span></h3><h3 class="post-title entry-title"><a href="http://hayatei.blogspot.com/2010/12/coil-and-insulation-in-high-voltage_17.html">COIL AND INSULATION IN HIGH VOLTAGE MOTORS</a></h3><h3 class="post-title entry-title"><span style="color: #351c75; font-size: large;"><span style="font-weight: normal;">The second part </span></span></h3><h3 class="post-title entry-title" style="font-weight: normal;"><span style="font-size: medium;"><a href="http://hayatei.blogspot.com/2010/12/measurement-of-insulation-resistance.html">Measurement Of Insulation Resistance</a></span></h3><h3 class="post-title entry-title"><span style="color: #351c75; font-size: medium;"><span style="font-weight: normal;">The 3rd part  </span></span></h3><h3 class="post-title entry-title"><a href="http://hayatei.blogspot.com/2010/12/insulation-resistance-value-required.html">Insulation Resistance Value Required For Operation</a></h3></div><div style="text-align: justify;">It is desirable that the coil and insulation of the motor is kept clean and dry. The dust accumulated on the surface of the coil prevents heat dissipation, and causes the deterioration of the insulation, though the deterioration depends on the type of insulation. Water penetrates through the joints of the outside lead wire and the cracklings of the insulation, thus reducing the insulation resistance.</div><br /> <div style="text-align: justify;">Attention to daily cleaning and prevention of moisture absorption leads to the prevention of megger reduction:</div><br /> <br /> <div style="background-color: yellow; color: red; text-align: center;"><u><span style="font-size: large;"> Use of Space Heaters</span></u></div><br /> <div style="text-align: justify;"><br /> </div><div style="text-align: justify;">When the motor is running, its interior is not so humid, and in dry condition, but absorbs humidity at rest.<br /> <br /> To prevent absorption of humidity, the space heater is to be energized immediately after the motor comes to stop and make the temperature inside of the motor 3 to 5ºC higher than the ambient temperature. </div><div style="text-align: justify;"></div><div style="background-color: yellow; color: red; text-align: center;"><span style="background-color: yellow; color: red; font-size: large;"><span style="font-family: Arial;">Drying</span></span> </div><div style="background-color: yellow; color: red; text-align: justify;"></div><br /> <br /> <div style="text-align: justify;">In case that drying is required due to the low insulation resistance caused by absorption of humidity, the drying is to be carried out after the motor has been cleaned. The space heater, the blowing of hot air, or low current heating are to be used for drying. It is safer not to apply current heating when insulation resistance is 0.05 MΩ or less.</div><br /> <div style="text-align: justify;">In any case, the drying is to be carried out at a temperature of 75~85ºC, raising the temperature at a rate of up to 10ºC per hour.</div><br /> <div style="text-align: justify;">The drying is to be continued, measuring the insulation resistance every several hours until insulation resistance remain constant for more than 24 hours.</div><br /> <div style="text-align: justify;">The change of insulation resistance due to the drying is shown in Fig. 1-2 (a-b).</div><br /> <div style="text-align: center;"><a href="http://hayatei.blogspot.com/2010/12/insulation-resistance-value-required.html"> </a><br /> <div align="center" class="MsoNormal" style="margin: 0cm 19.2pt 0.0001pt 18pt; text-align: center;"><br /> </div><a href="http://hayatei.blogspot.com/2010/12/prevention-of-megger-reduction-and.html"><img alt="http://img101.herosh.com/2010/12/18/815714691.jpg" src="http://img101.herosh.com/2010/12/18/815714691.jpg" /></a> </div><div style="text-align: center;"></div><div style="text-align: center;"><div align="center" class="MsoNormal" style="background-color: yellow; color: red; margin: 0cm 19.2pt 0.0001pt 18pt; text-align: center;"><span style="font-size: large;"><span style="font-family: Arial;">Fig.1.2-a Temperature correction curve </span></span></div></div><div style="text-align: center;"><br /> <br /> <br /> <a href="http://hayatei.blogspot.com/2010/12/prevention-of-megger-reduction-and.html"><img alt="http://www9.0zz0.com/2010/12/20/09/159936385.png" src="http://www9.0zz0.com/2010/12/20/09/159936385.png" /></a></div><div style="text-align: center;"><div style="background-color: yellow; color: red; text-align: center;"><div class="MsoCaption" style="margin: 0cm 19.2pt 0.0001pt 18pt;"><br /> <span style="font-size: large;">Fig.1-2-b : Change in Insulation .Resistance</span></div></div></div>

Prevention Of Megger Reduction and Drying

This post is the 4th part of COIL AND INSULATION IN HIGH VOLTAGE MOTORS The second part Measurement Of Insulation Resistance The 3rd part   ...

more information

Variable speed drives are cost effective

<div class="separator" style="clear: both; text-align: center;"></div><div style="margin-left: 1em; margin-right: 1em; text-align: center;"><br /> </div><br /> <br /> <div class="wp-caption alignright" id="attachment_1420" style="text-align: center; width: 225px;"><img alt="variable speed drive for pump" class="size-full wp-image-1420" height="280" src="http://engineering.electrical-equipment.org/wp-content/uploads/2009/08/atv_pump1.jpg" title="atv_pump1" width="215" /> </div><div class="wp-caption alignright" id="attachment_1420" style="text-align: center; width: 225px;"> </div><span id="more-1411"></span><br /> <div style="text-align: justify;">The motors of pumps and fans represent an important item of energy consumption in the building design.</div><div> </div><div style="text-align: justify;">The devices, used mainly for air-conditioning and heating, are most of the time centrifugal and are characterized by a variable power consume according to the cube speed. (See graphic below)</div><div style="text-align: justify;"><br /> </div><img alt="pump-curve1" class="alignright size-full wp-image-1425" height="238" src="http://engineering.electrical-equipment.org/wp-content/uploads/2009/08/pump-curve1.jpg" title="pump-curve1" width="388" /><div style="text-align: justify;"><br /> </div><div style="text-align: justify;">The use of the variable speed drives is not any more to show, their capacity to control the speed of the engines offers substantial profits of energy. A pump for example, needs only 20% of power to run at 60% of its speed.</div><br /> <div style="text-align: justify;">Beyond these advantages, the variable speed drives offer other possibilities of economies, in particular at the time of the building design and building maintenance.</div><br /> <br /> <div style="text-align: center;"><span style="background-color: yellow; color: red; font-size: large;">Building design</span></div><br /> <br /> <div style="text-align: justify;">The majority of the drives are able to provide information of current, voltage, power and energy (kWh) consumed by the motor, either on local display or remotely by connection on a communication bus.<br /> <br /> Extract of the parameters list of a ATV71 (Telemecanique Altivar Variable Speed Drives )<br /> <br /> “LCr” motor current<br /> <br /> “UOP” motor voltage<br /> <br /> “APH”: motor energy consumption in kWh<br /> <br /> “UNT” unit, it changes automatically when the value reached the maximum format of the parameter<br /> <br /> “OPr”: instantaneous power consumed by the motor in % of the nominal power of the drive<br /> <br /> In all the cases where a precise counting is not necessary, it is possible to make the saving in separate sensors.</div><br /> <div style="text-align: justify;">The yield of a motor is about 95% with its nominal load. It drops when the load decreases because part of these losses is constant: control supply, internal ventilation of the drive. This phenomenon is mainly compensated by the reduction in the losses of commutation which are related to the output current of the drive. Moreover for small drives (few kw), the power consumed by the auxiliaries is perfectly negligible.</div><br /> <div style="text-align: justify;">Consequently, the power consumed by the motor gives a good indication of total consumption and the precision about a few % is sufficient in the majority of the cases.</div><br /> <div style="text-align: justify;">The variable speed drives show another interesting characteristic. It comprises, on the network side, a rectifying bridge followed by condensers filtering which smooth the voltage and correct in more the power-factor. A motor having a cos φ of 0.8 will be seen, upstream the drive, with a cos φ near to 1.</div><br /> <br /> <br /> <div style="text-align: center;"><span style="font-size: large;"><span style="background-color: yellow; color: red;">Building maintenance</span></span></div><br /> <br /> <br /> <br /> <div style="text-align: justify;">The fact that the power grows like the cube speed offers interesting possibilities of detection, the measurement of this parameter makes it possible to identify anomalies which would be not very visible by the speed measurement alone.</div><br /> <div style="text-align: justify;">By supervising the histogram of the power according to time it will be possible to detect a clogging of pump or a clogging of dirtying of ventilation. It will be enough to parameterize a threshold of detection to trip an alarm making it possible to carry out a maintenance action.</div><br /> <br /> <a href="http://engineering.electrical-equipment.org/energy-efficiency-motors/cost-effective.html#more-1411">http://engineering.electrical-equipment.org/energy-efficiency-motors/cost-effective.html#more-1411</a><br /> <div style="text-align: center;"></div><div style="text-align: center;"></div>

Variable speed drives are cost effective

    The motors of pumps and fans represent an important item of energy consumption in the building design. The devices, used mainly for...

more information