OK to bypass genset thermal switch?

[N43Grace]

The exhaust fan failed that cools my enclosed Nextgen 5.5kw genset by removing the hot air from the clamshell enclosure, tripping the thermal switch/breaker when it got too hot in there.

Since then I've tried to use the genset by removing the clamshell enclosure and overhead floor panels to allow it to run without needing the exhaust fan but the thermal breaker keeps tripping.

I've ordered a new one but we are cruising and not able to get it for awhile, so hence my question-

As long as I've ruled out other reasons for tripping the switch/breaker is it OK to bypass it for awhile until I can get a replacement?

[SailingHarmonie]

There are only two reasons for tripping the thermal switch:
1: the genset is overheating
2: the thermal switch has gone bad.

If you know the the switch is bad, bypassing it is your only option. It the genset is overheating, then the consequences of letting it run are difficult to predict.

[wholybee]

If I understand correctly, the exhaust fan failed, the genset overheated, and the thermal switch tripped. Now you want to bypass the switch? Have you fixed the fan?

If the genset is overheating and the thermal switch is stopping it, bypassing the switch is a very bad idea. If the fan is fixed, and you can confirm the genset is not overheating, then if could be bypassed temporarily until it can be replaced.

[N43Grace]

The genset engine itself is not overheating and can run for hours without a problem. The switch cuts off the charging, not the engine.

I believe the thermal switch/breaker originally tripped because the exhaust cooling fan failed. The manufacturer tells me that after it's tripped a few times it can fail.

My temporary solution that is my question is to REMOVE the clamshell and OPEN up the floor panels over the genset when running, which should prevent the alternator and wiring from getting to hot in an enclosure, which is the purpose of the thermal switch.

Bypassing a breaker is a scary thing for an amatuer so I'd like your feedback about the above- IF I open things up while its running and bypass the breaker would there be a problem I'm not anticipating?

[ttex]

Do not bypass it if you don't know what your doing.

[Brioche]

Opening the area up to keep it cooler is a possible solution, but carries a risk unless you know the switch is faulty. If the setup allows, you could test the switch itself by removing it (plugging holes if needed) and locating it in a cooler place with extended wires. If it still trips, the switch is bad and you could better risk bypassing it. If it does not trip, that tells you something is still overheating and it should not be bypassed.

[SailingHarmonie]

Originally Posted by N43Grace

The genset engine itself is not overheating and can run for hours without a problem. The switch cuts off the charging, not the engine.

I believe the thermal switch/breaker originally tripped because the exhaust cooling fan failed. The manufacturer tells me that after it's tripped a few times it can fail.

My temporary solution that is my question is to REMOVE the clamshell and OPEN up the floor panels over the genset when running, which should prevent the alternator and wiring from getting to hot in an enclosure, which is the purpose of the thermal switch.

Bypassing a breaker is a scary thing for an amatuer so I'd like your feedback about the above- IF I open things up while its running and bypass the breaker would there be a problem I'm not anticipating?

If you KNOW there thermal switch is bad then you can bypass it. You say that opening the enclosure up SHOULD supply enough cooling. Do you know that to be true?

But it sounds like you are guessing the thermal switch is bad, and you are hoping there is enough cooling.

[Scrimshaw4]

I believe it was stated that the breaker tripped even after the cover was removed etc. While the mfg. indicated that the switch can fail after multiple trips that's not a statement that the switch has failed and is prematurely tripping. Without a heat gun to confirm that it's running within range you run the risk of actually overheating the generator and then dealing with a much larger problem. While main engine recharging may be use more fuel until the new fan arrives but it's less than having to rebuild an overheated generator. Particularly if what's actually overheating could be a fire hazard before it fails. Your Call. JMHO

[donradcliffe]

The generator was designed for forced air cooling of the coils. It was also designed to trip off if the coils get too hot. The fan has failed, and opening the enclosure has given you another overtemperature trip.

The only way to safely run the genset would be to put an external fan on the coils. Do not bypass the thermal switch.

[SV__Grace]

BRILLIANT test for this situation, I’ll try that, thanks!
🙏

Originally Posted by Brioche

Opening the area up to keep it cooler is a possible solution, but carries a risk unless you know the switch is faulty. If the setup allows, you could test the switch itself by removing it (plugging holes if needed) and locating it in a cooler place with extended wires. If it still trips, the switch is bad and you could better risk bypassing it. If it does not trip, that tells you something is still overheating and it should not be bypassed.

[team karst]

Is the switch in discussion the Klixon 50A circuit breaker? Be aware that all of the 120v current runs thru that device.
I have same genset, and a future improvement is to run a brushless 120v fan. The cheap DC fans have shorter life. Actually, the supplied fan had an interference between the squirrel cage and the housing, and i tossed it out.

[N43Grace]

Sure looks like it, I'll remove and check. Knowing the part mfr will make it easier and cheaper to source and replace.

Good to know about the brushless fan. Can you point me to a replacement for the one that came with the unit?

Originally Posted by team karst

Is the switch in discussion the Klixon 50A circuit breaker? Be aware that all of the 120v current runs thru that device.
I have same genset, and a future improvement is to run a brushless 120v fan. The cheap DC fans have shorter life. Actually, the supplied fan had an interference between the squirrel cage and the housing, and i tossed it out.

[team karst]

Redbutton. Marked with a 50. I sold mine, and have a unusual 120/240V switching system and associated breakers in carlon boxes. I haven’t looked in earnest for the 120V fan, but they do exist in squirrel cage config.