Megaohms

Paul S_3

I just want some info on a megohmeter .what does it do and how to use it and when should I check a compressor with it?

Techman

lots-a-ohms

Using a megohmeter is usually done on a PM program to check the comps windings .Now a days the megohmeter can be battery powered,prior to this "new" type the meter was hand cranked to generate the power.Basicly you check  out one winding at a time,say 3 ph, and you keep increasing the ohm's until you get a "short to ground".then you record that reading and compare that reading to the next reading at the next PM.The readings tell you if the oil/refrigerant/windings are still good or if the oil/filter drier need to be changed.The "short to ground" reading is supposed to be so high that the winding are perfecty good .Its the low readings that mean the winds are on their way out or are out .