Kohler generator issue

[User Name]

Hey guys, might be a long shot but thought I'd try. Just did a new install of a kohler 20rca generator. Everything all done, can run the generator in manual, can put the generator in auto, but it won't start or transfer if the power is shut off, it just sits there. It's like it knows the power is there, but when it's shut off, it still thinks the power is there.

On the transfer switch there's some status indicators, and on the generator there's some status indicators showing where the power is coming from, both have never lit up. But the digital display on the generator works.

I personally think the transfer control board is bad, but all the LED lights on the board are lit up. The dealer that sold it to us doesn't know, and doesn't think it's the control board because they've never had one go bad. Well someone's got to be the first right? He tried to say it was my wiring, but I followed the manual, and I have 2 other identical units for the same customer I did along side this project and they work fine.

I'm just kind of rolling the dice and hoping someone here has had the same problem. I've combed through both the transfer switch and generator for loose connections or something unplugged, can't find anything. Kohler is no help, they won't talk directly to anyone, you have to be a dealer. Problem is my dealer doesn't know what to do .

 

[hillbilly1]

Which transferswitch does it have? One uses a two wire start, the other appears to be a modbus connection.

 

[User Name]

I believe it's the RXT model. There's 4 wires via shielded cable that connect the generator to the transfer switch, Pow + Com 12V battery power and A and B of which I don't know their function.

 

[hillbilly1]

I’ve only used the RDT models, which is a simple two wire start from the transferswitch, don’t know if there is something that has to be enabled. A and B is a com loop, be sure the polarity is the same on both ends.

 

[User Name]

Yup I've double triple checked they are landed right.

 

[hillbilly1]

If it’s like a lot of buss communications, a dc voltmeter will fluctuate 0-2 vdc if it’s talking. If it is steady, or no voltage, it’s not communicating. Im assuming you checked the 12 vdc side at the transferswitch end?

 

[User Name]

Yup I tested my battery voltage at the transfer side.

I can try checking the A/B connections for voltage.

 

[Odie77]

I was a Kohler tech at a dealer for several years. From my experience I will tell you check all the factory connections. Was very common to have spade terminals with broken wires from improper crimping or the spade not properly seated on its tab. Also double check that the factory harness is going to the proper terminals on the contactor.

 

[Birken Vogt]

Once and only once I had one where the A and B wires were reversed in the terminal block at the genset. Check your installation manual which has the schematic at the back that they are correctly landed on the factory side.

Beyond that, check PWR, COM, A and B reference ground at the genset. Write down the values. Now go to the switch and check again. Should be the same values.

If you have zero lights at the transfer switch, I suspect your PWR and COM have a problem. IIRC you should at least get one green light when 12VDC via PWR and COM is landed correctly on the switch board.

There was a time when the green Phoenix connector with the silk screening was not available so they went to a blank one. I had an electrician wire it mirrored that time because the silk screening on the circuit board needs a mirror to see.

 

[User Name]

Once and only once I had one where the A and B wires were reversed in the terminal block at the genset. Check your installation manual which has the schematic at the back that they are correctly landed on the factory side.

Beyond that, check PWR, COM, A and B reference ground at the genset. Write down the values. Now go to the switch and check again. Should be the same values.

If you have zero lights at the transfer switch, I suspect your PWR and COM have a problem. IIRC you should at least get one green light when 12VDC via PWR and COM is landed correctly on the switch board.

There was a time when the green Phoenix connector with the silk screening was not available so they went to a blank one. I had an electrician wire it mirrored that time because the silk screening on the circuit board needs a mirror to see.

Yup sadly to say this was it. A and B were backwards in the generator. I still don't understand how it got missed. I looked at 2 trips, had the plumber hooking the LP look at it and we still missed it. I think because it's A B Pow Com in the transfer switch, then Com Pow B A in the generator it had me screwed up. Well live and learn for the next one.