wilko, Are you using that Ebay AVR on one of the Coleman Powermate gens? I have been having a PITA of a time with my Coleman 6875. When i got it, it was not producing power. The BJT and the Darlington transistor were toast. So I opted to replace them. After they were in, still nothing. I read somewhere about re-magnetizing the exciter with 12V, So i did. I jumped across the brushes and voila power, only it was 144 volts.....not 120. Checking the engine idle and putting the A/C spoce meter on it, it was running at 60Hz, so it has to nobe the AVR that is the problem. I do some checking, and the Darlington I put in was sorted, as was one of the BJt's again. likely from jumping the 12v?......So I bough virtually all the components to rebuild the entire board based on the schematic on pg1 as well as the some recommendations for a different Varistor at S2. Back to no power. The only components I hadn't replaced were the resistors at R1-3 and R5. Mostly because i forgot to order them. While they do appear to be okay on the outside, with a minimal mark on one of them, they all test OK and are within range for their values.
Now I am getting like 2VAC at the outlets. So, I moved to have the AVR external, so I can do some prodding with the meter. I Jumped the 12v across the exciter brushes and got 30vac momentarily at the power outlets. tried it again, and D7 Let the magik smoke out. No worries, I bought spares, but now I am back to getting 144VAC. So i KNOW that the coils and exciter are working. I just can't get the darn AVR thing right.

Hi Chris, I'm impressed you can rebuild the AVR but really they are so cheap off fleebay you may be better off replacing the lot providing the working voltages are the same. Some eBay sellers do state what they are.
I'm not sure your Coleman is anything like mine. My generator was a Kraftech, China derivation from a Honda design. Mine was a 3 phase unit that unfortunately got burnt out due to heavily imbalanced single phase loading. Realising 3 phase was totally unsuitable for my application I rewound it as best I could as a single phase generator. All my problems have been with the number of turns required on windings, not the AVR. My AVR is for a brush type rotor and has 6 wires. 2 wires are sense wires getting about 18vac sample from the output voltage. 2 are from the rotor excitation coils and should be about 70 vac. The last two wires feed the rotor slip rings. Can be up to nearly 100 vdc on full load.
See my earlier posts and Tady43's in this thread.
Cheers

 

Hi Chris, I'm impressed you can rebuild the AVR but really they are so cheap off fleebay you may be better off replacing the lot providing the working voltages are the same. Some eBay sellers do state what they are.
I'm not sure your Coleman is anything like mine. My generator was a Kraftech, China derivation from a Honda design. Mine was a 3 phase unit that unfortunately got burnt out due to heavily imbalanced single phase loading. Realising 3 phase was totally unsuitable for my application I rewound it as best I could as a single phase generator. All my problems have been with the number of turns required on windings, not the AVR. My AVR is for a brush type rotor and has 6 wires. 2 wires are sense wires getting about 18vac sample from the output voltage. 2 are from the rotor excitation coils and should be about 70 vac. The last two wires feed the rotor slip rings. Can be up to nearly 100 vdc on full load.
See my earlier posts and Tady43's in this thread.
Cheers

Rebuilding it was a viable option as the parts are cheaper then a new AVR board of that type. I think it cost me 35$ CAD for enough parts to rebuild it twice ( from Digikey). I have been fiddling with this thing for far too long though. I know it produces voltage, as mentioned I am currently getting 144VAC with the blown components. Maybe the components listed on the first page are not correct? My board is the exact same design as the images posted on page 1 of the thread.

I think what I need is some help with the diagnostics, or even retrofitting a 3rd party AVR. As mentioned, mine is the same as that on pg1. 7 wires including the brushes to the slip rings. 2 Black, 2 Yellow, 1 Blue and the + and - brushes.

Attached is a pic of the end bell label.

 

I also have a Coleman Powermate 5000 with a bad 0062479 AVR board. One of the thyristors exploded.
I could probably rebuild the board but I'm also noticing that there are several inexpensive new AVRs on ebay and the like. Has anyone looked into using a universal AVR to replace these? The main problem I'm seeing is that these are 6-wire setups and the Coleman's are a 7-wire, which includes brushes.
https://www.aliexpress.com/item/New...hase-For-5KW-5-5KW-6KW-6-5KW/32980780021.html

Any ideas?

 

I also have a Coleman Powermate 5000 with a bad 0062479 AVR board. One of the thyristors exploded.
I could probably rebuild the board but I'm also noticing that there are several inexpensive new AVRs on ebay and the like. Has anyone looked into using a universal AVR to replace these? The main problem I'm seeing is that these are 6-wire setups and the Coleman's are a 7-wire, which includes brushes.
https://www.aliexpress.com/item/New...hase-For-5KW-5-5KW-6KW-6-5KW/32980780021.html

Any ideas?

Hi Greydesk,

I am currently in similar situation, I have an old Coleman Powermate 6875 with bad AVR board. I am wondering if you managed to adapt one from AliExpress or Ebay?

Thanks!

 

Rebuilding it was a viable option as the parts are cheaper then a new AVR board of that type. I think it cost me 35$ CAD for enough parts to rebuild it twice ( from Digikey). I have been fiddling with this thing for far too long though. I know it produces voltage, as mentioned I am currently getting 144VAC with the blown components. Maybe the components listed on the first page are not correct? My board is the exact same design as the images posted on page 1 of the thread.

I think what I need is some help with the diagnostics, or even retrofitting a 3rd party AVR. As mentioned, mine is the same as that on pg1. 7 wires including the brushes to the slip rings. 2 Black, 2 Yellow, 1 Blue and the + and - brushes.

Attached is a pic of the end bell label.

Hi Chris,

were you ever able to retrofit a modern AVR to your old generator? Or were you ever able to bring down from 144 to 110 VAC you repaired AVR?
Thanks!

 

This is a AVR circuit ive reverse engineered & rebuilt which was faulty on a generator. It may be of some help.

Thanks