Hello,

Hopefully someone here can help me out because I am not understanding something.

I did an insulation test on one of our motors (a06b-1411-b153) and I got back some results that I need help with.

Insulation Results March 9 2022
Cable and Motor @ 1000V
U-G 13.7 MOhm
V-G 13.2 MOhm
W-G 13.4 MOhm
Cable and Motor @ 500V
U-G 15.8 MOhm
V-G 15.2 MOhm
W-G 15.1 MOhm
Cable Only 1000V (disconnected from amp and terminal strip)
U-G 125 MOhm
V-G 152 MOhm
W-G 170 MOhm
Cable Only 500V (disconnected from amp and terminal strip)
U-G 125 MOhm
V-G 167 MOhm
W-G 177 MOhm
Motor Only 1000V (disconnected from terminal strip)
U-G 1 GOhm
V-G 1.5 GOhm
W-G 1.4 GOhm
Motor Only 500V (disconnected from terminal strip)
U-G >550 GOhm
V-G >550 MOhm
W-G >550 MOhm
Cable and Motor @ 1000V (after all previous tests)
U-G 49.5 MOhm
V-G 49.5 MOhm
W-G 49.8 MOhm
Cable and Motor @ 500V (after all previous tests)
U-G 53.4 MOhm
V-G 53.2 MOhm
W-G 53.1 MOhm


My questions are:

Why did my cable and motor insulation results jump up from around 13-14 MOhm to 50MOhm after reconnecting everything?

Why is my insulation results lower when cable and motor connected versus higher when disconnected?