Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 16-03-2023, 10:11   #1
Registered User

Join Date: Jan 2020
Posts: 3
OK to bypass genset thermal switch?

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?
N43Grace is offline   Reply With Quote
Old 16-03-2023, 10:51   #2
Registered User

Join Date: Jan 2023
Posts: 290
Re: OK to bypass genset thermal switch?

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.
SailingHarmonie is offline   Reply With Quote
Old 16-03-2023, 11:08   #3
Registered User

Join Date: Mar 2016
Location: San Francisco
Boat: Morgan 382
Posts: 1,409
Re: OK to bypass genset thermal switch?

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.
__________________
-Warren
wholybee is offline   Reply With Quote
Old 17-03-2023, 06:29   #4
Registered User

Join Date: Jan 2020
Posts: 3
Re: OK to bypass genset thermal switch?

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?
N43Grace is offline   Reply With Quote
Old 17-03-2023, 06:53   #5
Registered User

Join Date: Jun 2011
Location: Texas
Boat: Baba 35
Posts: 350
Re: OK to bypass genset thermal switch?

Do not bypass it if you don't know what your doing.
ttex is offline   Reply With Quote
Old 17-03-2023, 08:15   #6
Registered User
 
Brioche's Avatar

Join Date: May 2018
Location: Catskill
Boat: Dufour 29
Posts: 150
Re: OK to bypass genset thermal switch?

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.
Brioche is offline   Reply With Quote
Old 17-03-2023, 08:17   #7
Registered User

Join Date: Jan 2023
Posts: 290
Re: OK to bypass genset thermal switch?

Quote:
Originally Posted by N43Grace View Post
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.
SailingHarmonie is offline   Reply With Quote
Old 17-03-2023, 09:35   #8
Registered User

Join Date: Jun 2009
Location: Annapolis, MD
Boat: Gozzard, 44CC, 50'
Posts: 492
Re: OK to bypass genset thermal switch?

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
Scrimshaw4 is offline   Reply With Quote
Old 17-03-2023, 09:44   #9
Registered User

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 6,112
Re: OK to bypass genset thermal switch?

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.
donradcliffe is offline   Reply With Quote
Old 17-03-2023, 10:20   #10
Registered User
 
SV__Grace's Avatar

Join Date: Dec 2019
Location: Currently cruising PNW
Boat: Nauticat 43 ketch
Posts: 742
Images: 5
Re: OK to bypass genset thermal switch?

BRILLIANT test for this situation, Iíll try that, thanks!
🙏

Quote:
Originally Posted by Brioche View Post
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.
SV__Grace is offline   Reply With Quote
Old 17-03-2023, 12:46   #11
Registered User

Join Date: Mar 2021
Location: Flagler County, FL, USA, Earth
Boat: Lagoon 380
Posts: 1,102
OK to bypass genset thermal switch?

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 is offline   Reply With Quote
Old 18-03-2023, 08:20   #12
Registered User

Join Date: Jan 2020
Posts: 3
Re: OK to bypass genset thermal switch?

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?

Quote:
Originally Posted by team karst View Post
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 is offline   Reply With Quote
Old 18-03-2023, 08:41   #13
Registered User

Join Date: Mar 2021
Location: Flagler County, FL, USA, Earth
Boat: Lagoon 380
Posts: 1,102
Re: OK to bypass genset thermal switch?

Redbutton. Marked with a 50. I sold mine, and have a unusual 120/240V switching system and associated breakers in carlon boxes. I havenít looked in earnest for the 120V fan, but they do exist in squirrel cage config.
team karst is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Bypass Switch for Navigation/Monitoring Kerry1 Marine Electronics 2 22-07-2022 20:14
Genset/shorepower switch Tomtom39 Electrical: Batteries, Generators & Solar 4 26-11-2012 05:37
High Pressure Bypass Switch on Refrigeration System Fluenta Plumbing Systems and Fixtures 1 06-09-2012 04:36
Bypass Accumulator Tank ? HarveyN Plumbing Systems and Fixtures 9 15-06-2010 22:04
Lewco Alternator Bypass Control Wojo Electrical: Batteries, Generators & Solar 4 13-01-2009 03:43

Advertise Here


All times are GMT -7. The time now is 07:18.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.