Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/339575
EQUIPMENT MANAGEMENT 15 AGGREGATES MANAGER July 2014 7H[W,1)2WRRUYLVLWZZZDJJPDQFRPLQIR Insulation resistance testing is another common test that can be performed. Motor insulation systems may deteriorate because of contamination, mechanical movement, cracking, aack by solvents, mechanical impact, or many other factors. A megger test places a voltage across the ground insulation. e megger test voltage is usually direct current (DC) and larger than the normal operating voltage, but not large enough to damage the insulation. A megger test is not a pass/fail test, but a measurement of condition. e recom- mended test voltages for this test and minimum winding resistance are found in Table 4. W hile proper motor maintenance is critical, selection of the right motor for the application is actually more important and can prevent many of the failures outlined in this article. Applications in severe and extreme environments require a more rugged motor. Selecting the proper motor for a specific application will provide beer system performance and reduce unscheduled down time. AM Motor Rated Voltage Clean Winding Test Voltage Minimum Insulation Resistance (Megohms) <1000 V 500 5 Recommended test voltages Table 4 John Malinowski is the general prod- uct manager, general purpose and severe-duty AC motors, for Baldor Electric Co. He can be reached at 479-648-5909.