The Fieldpiece Digital Megohm Meter, model SMG5, is a compact standalone meter designed for checking HVAC compressor insulation. The SMG5 provides a 1000V voltage source, monitors current, and displays the resistance between the test points. Maximum current output is <1mA. It can be used to determine the condition of insulation from winding to ground in a motor, compressor, or transformer. Includes a case, alligator clip lead tip and leads with removable tips. To test resistance, a DMM supplies low voltage (<1V) to the test points and is capable of delivering only a few milliamps. It's not a high enough voltage to detect high resistance problems that might indicate moisture and other contaminants and it's not enough current to measure lower values of resistance.
Predict compressor failure
1000VDC stresses insulation to measure up to 2000Mohms