MEP 803A (120V to L2 but not L3)

[Rockbottomfarm]

I have owned several 802 and 803 generators but this problem is a first for me. When set in 120/240 mode power should be to L1 and L3. The set in question has power to L1 and L2 but not L3 (L1 and L2 are both 120V to L0). To complicate matters further the voltage meter is reading correctly but the load meter isn't registering. I am starting the troubleshooting process and verifying wiring. I thought I would toss this out in the event there is a common issue that might save me some time. Thanks in advance for any help you can provide.

 

[Guyfang]

First check the wires to the K1, then from K1 to the output terminals. If that's not it, check the wires to and from the S8. I would bet someone switched two load wires.

 

[DieselAddict]

Also try the 3ph/208 setting on the reconnect switch. See if you still have a problem.

 

[Guyfang]

Things like this led me to buy a phase checker, or Rotational Indicator. Hook it to the load terminals, turn on the power and see if the lights showed me right or left rotation. Yeah, you had to put the set in three phase operation, but for us, it was always in three phase. If two output wires are switched, it showed left rotation. If a phase was missing, one of the three lights would not come on, and the rotational indicator would not show a direction. VERY handy tool.

No generator AC repair was complete without using this device. I learned the hard way. We received a "repaired" set, and didnt check it. Hooked it up to a radar. Turned it on. The coolant pump, a three phase motor, turned backwards. Yes, the pressure was less than normal. But, it still did manage to pump 50 gallons of coolant out onto the ground. It was a while before I was Mr. Popular again.

 

[DieselAddict]

Yea, a rotation meter is a very handy tool!

 

[Guyfang]

Cheap, too!!