AC voltmeter not accurate

[woodmann]

AC voltmeter on my MEP-002A will only go to about 200 when the genny is set on 240V/1Phase. On 120V, it will only go to about 100. I tried adjusting the screw in the face and actually that is what got me to 100/200 (it was about 90/180 before that.)

I tested across L1 and L3 lugs and got a consistent 240 on a digital meter.

Anything else I can try with the guage or is it no good?

Anyone sell a direct replacement?

Thanks

 

[Speddmon]

it could either be the gauge or the CT/CVT assembly. If it's the gauge, it's an easy and fairly cheap replacement. Delk's Army/Navy surplus should have them and pretty reasonably priced. If it's the CT/CVT assembly, that one will cost you quite a bit more. You might be better off putting a secondary volt meter on from e-bay or something like that. If you really want to keep it stock, the CT/CVT assembly can be had (I even have some) but they are not cheap or easy to install.

 

[woodmann]

Speddmon,

Can you tell me what the CT/CVT assembly is?

 

[Speddmon]

CT/CVT...Current Transducer/Current Voltage Transducer (or something very similar to that). It is an assembly of transformer coils in the output box located on the side of the set. It is where the metering and voltage regulator feedback signals come from. It consists of at least 3 different coils per phase.

 

[woodmann]

If that was bad would I still be reading a steady 240 output?
If so I guess it only really affects the guage?

 

[Speddmon]

That's why it has different coils per phase. One of them is the voltage signal, one of them is the amperage signal and one is the VR feedback. If it's only the metering devices that are not working, that's not a big deal. The one important one is the VR feedback.

 

[Isaac-1]

One more thing to check, see if htere is corrosion on the connectors on the back of the meter, etc. Corrosion will increase resistance and lower the voltage going into the meter causing it to read low.

Ike

 

[woodmann]

Speddmon,
Thanks for the info. I'll search the TM'S and see if I can find a testing procedure to isolate the problem. I'll probably have more questions when I start digging around.

Isaac-1,
Thanks for the tip. I'll check that.

 

[OPCOM]

The voltmeter can be checked by opening the control panel and checking the voltage across it. It ought to be the same as indicated on the face.

 

[LuckyDog]

bump

Any luck?