Breaker issue
- Thread starter Fordguru
- Start date
danemayer
Well-known member
When the generator is turned off, the transfer switch contactors break contact on the generator side and if you're plugged into shore power, then make contact with the shore power side. If you do this under load, there may be arcing and the arcing could be producing electrical spikes. It's possible a spike could affect Power Converter output.
As a good practice, you might want to shut off the main 50 amp breakers in your interior circuit breaker panel before starting or stopping the generator, and before plugging into or unplugging from shore power.
That all said, most of these 12V DC breakers trip based on thermal expansion. And tripping is usually from excess power across the breaker for at least a few seconds. I'd think a momentary spike would have to be pretty big to trip a thermal breaker.
But that's the best theory I've got.
BTW, if you do have spikes when the transfer switch operates, the contactors may be pitted, which eventually will lead to overheating and complete failure. It may be time to try and clean the surfaces or replace the contactor assembly. If you try shutting of the 50 amp breakers before making power connections/transferring power, and it gets rid of the breaker problem, a call to Progressive Dynamics may be in order.
As a good practice, you might want to shut off the main 50 amp breakers in your interior circuit breaker panel before starting or stopping the generator, and before plugging into or unplugging from shore power.
That all said, most of these 12V DC breakers trip based on thermal expansion. And tripping is usually from excess power across the breaker for at least a few seconds. I'd think a momentary spike would have to be pretty big to trip a thermal breaker.
But that's the best theory I've got.
BTW, if you do have spikes when the transfer switch operates, the contactors may be pitted, which eventually will lead to overheating and complete failure. It may be time to try and clean the surfaces or replace the contactor assembly. If you try shutting of the 50 amp breakers before making power connections/transferring power, and it gets rid of the breaker problem, a call to Progressive Dynamics may be in order.
Flick
Well-known member
When dealing with any problem, eliminating possible weak links is the best way to move forward. The 80a is cheap and replacing is easy. Eliminate it as the cause before you dig further.
LBR
Well-known member
Those style of breakers are not well liked on the many FaceBook DIY Solar pages and groups I'm on. Many of the solar gurus have been there done that with those, and retort to common breakers in a minibox.
They contend the breakers are either weak, over-sensitive to voltage spikes, "cheap"....they just are not well liked for the PV input nor controller to battery protection. I personally can't condem them as many here use them as an upgrade for their hydraulic levelup/slides circuit.
Even tho it is an 80A rather than the normal 50A, it may be worth some time and $$$ to try another quality CB in it's place.
danemayer
Well-known member
The breaker may be weak and it could be a poor performing breaker.
BUT, if it actually trips when you shut down the generator (every 5th time), you have to ask yourself how the generator, which produces 120V AC, triggers a problem on your 12V DC system.
One possibility is the generator somehow backfeeding a 12V spike from the generator's starter, back to the battery. But the 80 amp breaker probably isn't in that direct path, so maybe this is a less likely possible cause.
Another possibility is something in the generator shutdown affecting the Power Converter; the Power Converter having 12V DC output that goes directly to your 80 amp breaker. If the Power Converter is producing a spike that trips the breaker, that could trip the breaker, but you have to ask what's causing it to produce a spike when the generator shuts down.
As the generator shuts down, as soon as voltage on the L1 leg drops below 105V, the contactors in the transfer switch actuate.
So, my best theory is that something in the transfer switch operation is causing the Power Converter to generate a spike on the 12V DC output, tripping your 12V DC breaker.
That said, the breakers are usually thermal expansion, driven by excess current. And they usually take at least several seconds of excess current to heat up enough to trip. So a momentary spike might have to be pretty significant, or perhaps the breaker being weak would cause a brief spike to trip it.
A new breaker might get rid of the problem, but might not fix an underlying condition. If you have pitting on the transfer switch contactors, it'll get worse over time and eventually you'll have a high resistance problem at the transfer switch.
BUT, if it actually trips when you shut down the generator (every 5th time), you have to ask yourself how the generator, which produces 120V AC, triggers a problem on your 12V DC system.
One possibility is the generator somehow backfeeding a 12V spike from the generator's starter, back to the battery. But the 80 amp breaker probably isn't in that direct path, so maybe this is a less likely possible cause.
Another possibility is something in the generator shutdown affecting the Power Converter; the Power Converter having 12V DC output that goes directly to your 80 amp breaker. If the Power Converter is producing a spike that trips the breaker, that could trip the breaker, but you have to ask what's causing it to produce a spike when the generator shuts down.
As the generator shuts down, as soon as voltage on the L1 leg drops below 105V, the contactors in the transfer switch actuate.
So, my best theory is that something in the transfer switch operation is causing the Power Converter to generate a spike on the 12V DC output, tripping your 12V DC breaker.
That said, the breakers are usually thermal expansion, driven by excess current. And they usually take at least several seconds of excess current to heat up enough to trip. So a momentary spike might have to be pretty significant, or perhaps the breaker being weak would cause a brief spike to trip it.
A new breaker might get rid of the problem, but might not fix an underlying condition. If you have pitting on the transfer switch contactors, it'll get worse over time and eventually you'll have a high resistance problem at the transfer switch.
I was leaning this way as well
going to do some searching, I no longer have any thermal breakers
