Voltage Problem MEP-002

[mtfleming]

Have a MEP -002. When it's running with a small load (500W), it works fine. voltage is fully adjustable. When I then add a load up to say 50%, the voltage drops to 200V (from 240V), and is no longer adjustable. What could this be? Thanks to all in advance for your help!

 

[Triple Jim]

It's likely that for some reason you don't have enough exciter field current. It could be a lot of things. I'd start with checking the diodes on the A4 board (in box under output lugs). If they're OK, I'd check the resistances of the windings of CVT1 against the resistances in the -34 manual. If those check out OK you should probably check the rotating diodes in the generator.

There are some troubleshooting procedures that can be very helpful in the manual too.

 

[jamawieb]

More than likely the voltage regulator. There are 2 adjustable pods on the voltage regulator R16 and R15 (I think), use a very small flat head screw driver and make 1 full rotation, then move it back to the original position. See if that helps.

 

[Guyfang]

While you are looking at things in the AC output box, look for loose wires and broken wires. Look at the solder joints on the A4 card.

 

[mtfleming]

Thanks to all!

 

[Guyfang]

Don't thank anyone, till you got it fixed!