MEP-804A Low Voltage - Voltage Regulator Question

[RonK]

I am troubleshooting a MEP-804A which has what seems to be a common issue: While it is held in START the voltage goes up to 230VAC
but as soon as it is released it drops to about 24VAC.

I have been doing some of the steps that are mentioned in the -24 manual and in various threads here.

The voltage regulator in this one is a 122-3054 P/N 30554SOCN88-22560

The manual lists 2 options none of which is this one: P/N 01- 21501-1 & P/N 01- 21501-2

I have done the measurement of the disconnected wires from Pins 1 & 3 of the regulator at 34 ohms.
The voltage pot test is 3K CCW and 13.5K CW


If someone can lend some clarity to the VR P/N confusion or suggest some tests that would be very helpful.
Thanks.

 

[Scoobyshep]

The AVR isn't taking over. What you're seeing is The flash voltage.

Sent from my SM-S908U using Tapatalk

 

[RonK]

Any idea which set of VR tests in the manual I should try given that my P/N doesn't match the manual?

 

[Guyfang]

Take a picture of the data sticker on the VR for us.

 

[kloppk]

From the pics posted below it appears to be a Libby. Green paint and Libby showing between the wires.

 

[RonK]

Take a picture of the data sticker on the VR for us.

Here are some pics. As I mentioned, The P/N on the generator doesn't match the 2 options mentioned in the manual.

 

[peapvp]

The Cage number 36024 on the AVR indicates that this unit was made by

LIBBY POWER SYSTEMS, LLC
Doing Business As (DBA)
Division Name
Address	35 SARGENT DR BETHANY, CT 06524 3135 UNITED STATES

check the fuse to the left of AVR first.

 

[jamawieb]

Need to look at the transformer beside the contactor to the far right. Usually the transformer burns up causing the issue

 

[RonK]

The Cage number 36024 on the AVR indicates that this unit was made by

LIBBY POWER SYSTEMS, LLC
Doing Business As (DBA)
Division Name
Address	35 SARGENT DR BETHANY, CT 06524 3135 UNITED STATES

check the fuse to the left of AVR first.

Fuse is good.

 

[RonK]

From the pics posted below it appears to be a Libby. Green paint and Libby showing between the wires.

Which of the two VR test options on the manual should I use?
The P/N on the regulator is none one of the two in the manual.
(P/N 01- 21501-1 & P/N 01- 21501-2)

 

[peapvp]

Which of the two VR test options on the manual should I use?
The P/N on the regulator is none one of the two in the manual.
(P/N 01- 21501-1 & P/N 01- 21501-2)

The part number on your AVR deciphers as follows:
30554SOCN88-22560
30554 => Cage Number 30554

Legal Business Name	DEPARTMENT OF DEFENSE PROJECT MANAGER-MOBILE ELECTRIC POWER
Doing Business As (DBA)
Division Name
Address	5850 DELAFIELD RD BLDG 324 FORT BELVOIR, VA 22060 UNITED STATES

SOCN 88-22560:

Three versions available:




I am not sure, but I don’t think either of the two tests in the manual apply to these three AVR’s

There might be a remote possibility that the test for TRC AVR in manual may work, but could possibly yield different test results

 

[RonK]

The part number on your AVR deciphers as follows:
30554SOCN88-22560
30554 => Cage Number 30554

Legal Business Name	DEPARTMENT OF DEFENSE PROJECT MANAGER-MOBILE ELECTRIC POWER
Doing Business As (DBA)
Division Name
Address	5850 DELAFIELD RD BLDG 324 FORT BELVOIR, VA 22060 UNITED STATES

SOCN 88-22560:

Three versions available:
View attachment 953863
View attachment 953864
View attachment 953865

I am not sure, but I don’t think either of the two tests in the manual apply to these three AVR’s

There might be a remote possibility that the test for TRC AVR in manual may work, but could possibly yield different test results

Thanks. That is my concern - I would like to avoid potentially expensive mistakes. I wonder if the resistance of the voltage pot might be the clue. 3K CCW and 13.5K CW does substantially agree with one of the options in the manual.