mep-003 volt meter

[scrapdaddy]

For you generator guys, I've got two mep-003 gen. and both AC volt meters are fogged. Condensation has formed inside the meters. I removed one meter and took it apart. What is the screw for in meter's face. I'm guessing to set the needle to zero? I think the water must be getting in there. I would like to silicone the back of it to seal it up. Comments

Thanks, Ron

 

[flyxpl]

I have the same problem on one of my mep-003 gens. Only the AC volt meter ha the problem .

 

[3dAngus]

On the screw in front, you can take a multimeter, measure the 220vac, and calibrate the meter on front for a more accurate quick reading. Sometimes those meters get off a little bit from a number of different causes with time and it might be helpful to get it to measure up right if not already.

 

[rosco]

You can always replace it, but if you don't want to, my procedure is to put it in a warm/hot dry place and let it set till the moisture is driven off. Outside in the sun will probably do it too, but if it leaks now, it probably always will. At the same time, I have had fogged guages function fo many years, not that I like it that way - don't want to spend the money to replace it. Calibrate it, and try your silicone, but that might look as bad as the moisture.

 

[cranetruck]

Silicone will not seal out the water molecules. The case will breathe the ambient air unless you have a hermetic seal. Let warm, dry ambient air take care of the fog, like mentioned by rosco.
In the end the only practical solution is a vented case.

 

[rosco]

Interesting - Vented, as in How? I am also thinking of guages in other applications, like a farm tractor.
Do you mean drilling a small hole in the rear of the case?

 

[scrapdaddy]

volt meter

Thanks guys, my computer gave it up and just got a new one. I took one ac volt meter apart. I let it dry out, but the screw in front was not attached to anything. The connection must of broke. I did get to clean up the lens abit before closing it up. I'm going to get that one running first, just to make sure the gauge works before moving to the other one. Hope the cover tarp does it's job now to keep the rain out. Seems like just the AC volt meters fog up?

 

[steelandcanvas]

Ron, The screw is used to calibrate the meter, see post #3. The screw on the meter cover fits into an upside down "U" on the meter face. Slightly turning this screw will allow a few degrees of needle swing in either direction. Adjust this to match the reading on a good digital voltage meter. Bjorn is entirely correct, sealing the meter will not prevent moisture from entering. Good design would have allowed the meter case to "breathe" and evaporate the collecting moisture.

 

[scrapdaddy]

Thanks, I did see that on the face, but it looked like it didn't come close to the adjustment screw. anyway I'll leave the other generator alone for now and see how this does. No sence in taking it apart if it's going to fog back up. The two gauges had some serious condensation in them.

 

[steelandcanvas]

The two gauges had some serious condensation in them.

Call Delk's and ask what replacement cost would be. They shouldn't be too expensive. It's always a good thing to have accurate meters that work.

 

[scrapdaddy]

will do! I agree

 

[cranetruck]

Interesting - Vented, as in How? I am also thinking of guages in other applications, like a farm tractor.
Do you mean drilling a small hole in the rear of the case?

Actually, yes, repeated cycles of humid warm days with cool nights, will essentially act like a pump and water will accumulate.
Built instrument cases for tractor trailers and ocean racing sail boat applications by the thousands over the years and always made sure there were breathing/drain holes.
One glaring example of an, IMHO, poorly designed housing is the 5-ton "Protective Control Box", which is welded shut, but still leaves the connector rubber seal to permit the "pumping" action to take place. Open one up and see how rust has taken over. They should be vented. Some (all?) of these boxes have an 1/8" pipe plug installed and that plug should have been left out, again in IMHO.

 

[wciguy]

I have had several frequency meters that were bad and bought digital frequency meters on ebay to replace them. Had a local shop cut some adaptor plates with a laser for mounting the rectangular digital meters where the round meters were. Works nice. This is especially nice for the frequency meter since it is an expensive two piece unit with a frequency converter mounted in the box feeding miliamps of current to the meter. Hooked the new meter to the voltage meter and taped off the old frequency meter leads.

Anyway, the adaptor plates would work for a digital volt meter, too. Will take $10 including shipping for one if anyone is interested.

 

[scrapdaddy]

That's a good idea, I have to see how mine work , still havn't got them running. The first one is locked up, I'll keep you posted. Thanks

 

[Keith_J]

I'm having this problem with my 002a. I took the ammeter apart last night, shattering the lock ring on the back to gain access. The problem was the damping magnet that had come loose from the fixture, pinching the aluminum damping vane (much like the damping vane on a reloading scale, eddy current damping).

I cleaned it up and re-attached the magnet, then adjusted the vane as it was bent slightly. Then calibrated according to Full Scale Deflection at 1 amp AC.

That screw on the front is the zero adjustment. The needle is balanced for panel mounting, note this when testing. The screw adjusts the hair spring tension.

My frequency meter was too far gone Probably will need a volt meter too.

ETA: The voltmeter tested fine. It even showed a tiny droop when connected to 240 volt service in the house and the AC kicked on.