MEP-806A Transformer Replacement Part

[mfanning4]

Hello, I have a MEP-806A Generator that will start and run, but not produce any voltage when holding switch to start or releasing. I have a contactor trip under voltage light illuminated. I did the 4.1 voltage regulator test, from the TM, and determined that the transformer may be the issue, as terminals 11 and 12 do not produce power. I checked for continuity through the droop current transformer, and it was ok. I did find the 2 wires going from the main transformer to TB1 were both shorted out and burnt through in a few places. I replaced those 2 wires and still having the same issues. Could this be a bad main transformer? Or how would i go about sourcing a correct Libby transformer replacement? Any advice or feedback is welcome! thank you

 

[Guyfang]

Welcome to the Forum.

The easiest way to try and locate a part is to start a "Parts Wanted" Thread. Posting the part # and NSN helps a lot also. You are missing the Quad Circuit Fuse mod on the set. Not good for your gen set to operate it with out the Mod. Have you tested for continuity between the Transformer terminals 11 & 12? Is the A1, (Volt Regulator) look like its been changed? Its also not a bad idea to insure that the compleat VR system is all Libby made. See attached sheet.

 

[mfanning4]

Welcome to the Forum.

The easiest way to try and locate a part is to start a "Parts Wanted" Thread. Posting the part # and NSN helps a lot also. You are missing the Quad Circuit Fuse mod on the set. Not good for your gen set to operate it with out the Mod. Have you tested for continuity between the Transformer terminals 11 & 12? Is the A1, (Volt Regulator) look like its been changed? Its also not a bad idea to insure that the compleat VR system is all Libby made. See attached sheet.

Hey thanks for the quick response!

I will have to look into getting that fuse mod installed. And I did not, test for that as of yet. Do you happen to know what pins are 11 & 12 on the transformer? I have not been able to find an accurate pinout spec for it.

I do believe the Volt Regulator is original, as I dont see any signs of it being replaced.

Also I saw a post somewhere along my searches of an upgraded voltage regulator that will bypass the transformer. Are you aware of this or do you have any feedback on it's success/failure?

Thanks again!

 

[Guyfang]

For the A1, Member @kloppk is the man to talk to. You are too new to send a PM. I will try and shake him up.

 

[kloppk]

For the A1, Member @kloppk is the man to talk to. You are too new to send a PM. I will try and shake him up.

Shook up
Click on my signature below to get to my listings in the forum classifieds.
Or click this -> Listings

 

[Guyfang]

Kurt, he is too new to PM to you. Have to maybe do it in reverse.

 

[mfanning4]

Shook up
Click on my signature below to get to my listings in the forum classifieds.
Or click this -> Listings

Hey thanks for the help! So I found your post for the updated voltage regulator and just have a couple questions before I pull the trigger on it.

This does bypass the transformer I am currently attempting to repair/replace, correct?

And if so, and if I'm understanding everything correctly, this upgraded regulator will essentially kill multiple birds with one stone as it will:
1 - replace/upgrade my current VR
2 - includes the fuse mod mentioned earlier
3 - will work regardless of the manufacturer of the transformer and related parts mentioned above.

Again I cannot thank you guys enough for the help thus far!

 

[kloppk]

Yes, you have it exactly correct.
You may not be able to PM me yet but my email address is in the listing.

 

[mfanning4]

Yes, you have it exactly correct.
You may not be able to PM me yet but my email address is in the listing.

Awesome! I will send you and email here shortly.

Thanks!

 

[mfanning4]

Yes, you have it exactly correct.
You may not be able to PM me yet but my email address is in the listing.

So I received your Voltage regulator upgrade and installed without issues. It seems to have fixed the problem we were having, but now it is showing a low frequency on the gauge, at ~48 Hz. The unit fires up just fine, the generator comes online, and all warning lights are clear, but the gauge is reading low. Do you know of a way to check/verify frequency on these machines? I want to try and rule out a malfunctioning gauge.

Thanks for all the help so far!

 

[kloppk]

A handheld voltmeter that can measure frequency will do the trick.

Also a handy device to have is a Kill-a-Watt meter. Great for measuring AC voltage, Frequency and load if something is plugged into its outlet.

Do you have the frequency switch set to 60?

 

[mfanning4]

A handheld voltmeter that can measure frequency will do the trick.

Also a handy device to have is a Kill-a-Watt meter. Great for measuring AC voltage, Frequency and load if something is plugged into its outlet.

Do you have the frequency switch set to 60?

Thanks, I'll have to look into getting a Kill-a-watt meter, but I do have a multimeter.

And yes, I do have it set to 60

But I should be able to get an accurate reading from the back of the gauge itself and the 110 outlet, correct?

Sorry for the confusion/questions, just want to make sure I'm understanding the system completely.

 

[Guyfang]

Just stick the DMM probes in the 120 volt outlet. That will tell you what you want.

 

[mfanning4]

Just stick the DMM probes in the 120 volt outlet. That will tell you what you want.

Perfect, thank you!

 

[kloppk]

The outlet should has 120 volts AC.
The back of the meter will have either 120 or 208 volts depending on the setting of the AM-VM switch. The assumes the voltage reconnect plate is in the 120/208 position.

 

[Ray70]

The Kill-A-Watt is a great thing to have. It's like $28 at Home Depot and probably cheaper on line.
Use it to test your gen, then during an outage you can plug it in someplace convenient in your house where you can quickly see what the generator is doing without even leaving the couch or putting down your beer!