1800 Diesel
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Rather than start a new thread I'll use this one since it's basically the same issue for me with an MEP-002A. At governed speed the generator is producing proper voltage and frequency (verified by a known good external meter). The problem is that the unit's freq meter generally pegs to the right. I checked voltage on the AC input side & read about 1.8V, obviously not 120V. I also removed the two AC connections and connected grid power and the freq meter pegs to the right. On the surface that seems to indicate a bad transducer but then why does it show the same results with only 1.8volts AC coming in? Another question, does the low voltage indicate bad transformer(s)? So far I haven't had to service one of those, but they do appear to be a PIA to remove and replace...Your Frequency transducer is probably shot. (upper left corner of your 4th pic.) an easy way to test it is to detach the 2 AC in wires on the left side of the transducer and attach a line cord in their place. Plug it into utility power and see if it reads 59-60 hz. If you still get nothing then most likely the transducer is dead. If by some slim chance you do get a good reading, then you will need to look at the rest of the system, probably starting with the transformer feeding the transducer.
Edit 1: Found TM-12 instructions for resistance testing T1 & T2 primary and secondary windings. Planning to get that done tonight or in the morning and will report findings.
Edit 2: Before I started removing wires connected to T1 transformer I found that the J9 amphenol connector was loose with only one or two threads engaged. I backed out the connector and cleaned up the pins & sleeves a little and reconnected. Now I have 120 volts at the AC input of transducer A3. Started up unit but still no good frequency reading. Tried a different freq meter and same results. Tried adjusting the transducer settings but no success. Also connected grid power to A3 & freq meter pegs to the left side. Verified wire numbers were correct at each connection on both AC & DC sides of A3. So now I've pretty much decided the A3 transducer is beyond salvage so I need to come up with a replacement.
Edit 3: Maybe it was a bad idea connecting my issue to this thread. Moderator--was this not the correct thing to do?
To update (and now I'm really lost):
Installed a known-good freq meter and transducer from an MEP-003A I have in the shop and then started up the MEP-002A and set it to 60hz using my external meter. The on-board meter is pegged past 65hz, same as the original meter/transducer.
I checked AC voltage into the transducer #2 terminal and got 120v (I connected my voltmeter black to L0 & red to #2.) I also checked TB5-13 across to L0 and got 120v. Got no voltage from L0 to TB-12.
Now for the really confusing part: I then disconnected the generator AC input wires and connected line voltage to the transducer at #1 & #2 and the frequency meter pegs to the right at 65hz +, just like when the unit is running. Does anyone have any ideas what's happening??
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