Kohler 20 kw nightmare

mfrausto73

Well I bought a Kohler 20 kw generator last year 2023 and it has been a pain in my rear. It trips my afci breakers. Everything imaginable has been done to figure out what is wrong. It happens when the transfer switch turns to generator power. Does anyone else out there have this issue.

Dave Angelini

Have you replaced the AFCI with a different make device? The more info you give the better result.
Are you offgrid? Who installed? Where are you? Tell us what is imaginable that has been done?

DanS26

You are condemning the generator but the most likely culprit is the transfer switch. An arc is being sensed at the transfer switch mechanism.  

I had the same problem and the only solution was to replace the AFCI breakers.

mfrausto73

Well for starters we changed the spark plugs that made fewer afci breakers trip. Tech also updated firmware. Played with settings on generator Voltage. Checked all connections to make sure everything was nice and tight. And upgraded my afci breakers to heavy duty Eaton breakers and still they trip. Generator has brand new spark plugs now and it is brand new as well. Any advice anybody experiencing the same thing as me with my Kohler 20KW.

mfrausto73

Quality generators installed my unit.

mfrausto73

I am in Houston Tx.

Dave Angelini

About 35 clients over the years using Kohler/Honda. The only problems have been the electronics being expensive. It usually fixes them for a long time. A good Genny.

With any generator problem, it should be easy to prove with another generator. I did not see that you mentioned a rather easy test to swap out the bad unit.

I would also try shutting down the grid first, then do the transfer if it can be done this way. Idea is
to eliminate the grid as a source.

mfrausto73

They are going to replace the transfer switch hopefully that fixes my headache of tripping afci breakers.

DanS26

Still under warranty?  If so good....I had to replace AFCI breakers with standard breakers.  Not code compliant on some circuits but it was way less expensive than replacing the transfer switch.

JRHill

"Well for starters we changed the spark plugs that made fewer afci breakers trip."

I am at a loss for words on that statement.

BB.

AFCI (Arc Fault Circuit Interrupters) detect an "arc fault" (sustained arcing on AC wiring) from monitoring the Radio Frequency (and other?) electrical noise on the AC lines. And one reason that folks have had problems with false AFCI trips from (for example) vacuum cleaner tripping--The brushes creating arcs can be detected by the AFCI as an "arc frequency signature".

I am guessing that, for example, in decades past, resistors where added to some models of spark plugs to reduce AM Radio interference... Changing plugs, specially to resistor types vs non-resistor, could reduce false AFCI trips--At least a guess on my part.

A short paper from Champion on several resistor type plugs:

https://www.gsparkplug.com/media/wysiwyg/technical-information/champion/Champion_Resistor_EN-F-ES.pdf

There are also "resistor plug caps" available:

https://torqueadvisor.com/resistor-vs-non-resistor-spark-plugs/

There are also several types of "resistor ignition cables" too:

https://autowiringpro.com/spark-plug-wires/

Can/does this cause AFCI false trips? Don't know for sure.

Otherwise, people have reported that AFCI's have been damaged from power surges (lightning, high voltage power line crosses), and just "electrically noisy" generators:

https://forums.mikeholt.com/threads/generator-causing-afcis-to-trip.137909/page

-Bill