Fordean
Senior Member
- Location
- New Jersey
- Occupation
- Electrical Contractor
1st test was to Move motor giving problem to another MCC Bucket. But still used same UG branch circuit to it. This ruled out bucket problems.
Voltage were good to all three phases. Cant remember exact number but 274, 278, And maybe one had a 269. Had 479, 478, and maybe 469 on all. The bad phase I believe had the lower voltage.
Only minor difference their. Did alot of moving around. Wires definitly damaged underground. Megger should bad Real Bad actually But still they worked. Only one came up out of bad range to good , but only in lower ohms scale. Still wasnt a good phase
Next question How to test motor. I megger it. I did not get bad reading on the way I did it. Want to double check procedure.. I need correct megger test for motor.
Test #1 Dont think this was a correct test.
I left all wires connected. 4 thru 9 wired for standard High voltage diagram. ( except the T1 T2 T3, I megged from their. Someone said I should megger T1 (Red lead of meg) and Ground T2,t3, to Case and to ( Black Lead meg).
Test #2 This test I know was a correct test.
I megger T1 (Red Lead Meg, Black to Casing) Fine. T2 (Red Lead Meg, Black to casing) T3 (red Lead Meg, Black lead to Casing) All these meg well. ( Remember All 4 thru 9 leads Tied for 480volts together,
Did not isolate these).
New Motor Got damaged I believe in very short period. Should have meg first. But wires looked brand new so I ignored. But they were damaged. After New motor had same results with original underground wiring.
Actually thought I found A complete sever of Yellow phase. Trying to find out if someone cut for a jumper, as we were testing, but I believe it was severed and fell apart after wiggling. And no one touched it. It was in bundle. Almost positive it was severed. THis was the Above Ground Portion. Could not pull nothing out of conduit underground.