If you are using a shunt trip breaker in your system...

Dr. Dickie

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Sep 23, 2020
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So I picked up a ABB SACE S5 circuit breaker with the 24V shunt trip that I plan to wire into my system. I have watched LithiumSolar's vids on his set-up.; and I have a question kind of related to that. He switched (with the center post on the breaker) the feed to his inverter so that if the system tripped, the PV array could not continue to feed the inverter. Makes sense.
However, every solar charge controller that I have had (I have a new Midnight controller coming, don't have it yet) wanted the battery to be connect to the controller first then the PV input. This make sense to me as the controller gets its power from the battery and you would want it powered up before hooking up the array input. IF the battery SOC gets too high or too low and the shunt trip flips the breaker, it shuts off battery power to both the inverter and the charge controller. However, the PV array would still be putting current into the solar charge controller--from what I understand that might be bad for the controller. I plan to wire the negative from the PV array through the center post of the breaker so that the inverter, the controller, and the PV array input, all get shut off in the event of a too high or too low SOC event (or critical fault from Batrium BMS) happens. Would there be any thing wrong or problematic about doing it this way?

 

daromer

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Only cheap controllers could be damaged from having solar connected while not battery is.

Proper controllers would never need to be tripped.

I wouldnt add the solar to same breaker personally and beware of the wiring diagram on the ABB. With that said its not dangerous adding the solar to trip but its not needed per set standards
 

Dr. Dickie

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Only cheap controllers could be damaged from having solar connected while not battery is.

Proper controllers would never need to be tripped.

I wouldnt add the solar to same breaker personally and beware of the wiring diagram on the ABB. With that said its not dangerous adding the solar to trip but its not needed per set standards
Okay, up to now, I have mostly had cheap controllers.
If they are not damaged by having PV on with no battery, then I probably will wire like LithiumSolar did.
Thanks I watched your vids to learn most of what I know about these trip breakers;)
 

daromer

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Those breakers are solid for the Price. Will last our lives easily hehe
 

OffGridInTheCity

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I've not had any trouble with my Midnites with the battery off but PV (to them) on. I have breakers physically at the Midnites to disable PV in case I want to work on them - but otherwise they stay on. Here's a pic of the PV incoming circuit breakers - 1 per midnite:
1615132379807.png


There is a large control box that joins the battery, charge controllers, inverter and other battery related stuff - where I have individual circuit breakers to disable each Midnite (DC in) and each Inverter (DC out) and the SACE shunt-trip to disable the battery itself (DC in). The SACE should be in the control box but I didn't have room. I've often disabled the Midnite circuit breakers at the control box to work on the battery/inverter system but left the PV input on at the Midnites - all with no trouble.
1615132598662.png
1615132416937.png




One side affect of 'not' wiring in the charge controller DC input to the shunt-trip is that I can still have power coming in from the Midnite even with the battery off - so its important to flip the charge controller circuit breakers before digging in to see why the shunt-trip went off :)
 
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Dr. Dickie

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Joined
Sep 23, 2020
Messages
122
I've not had any trouble with my Midnites with the battery off but PV (to them) on. I have breakers physically at the Midnites to disable PV in case I want to work on them - but otherwise they stay on. Here's a pic of the PV incoming circuit breakers - 1 per midnite:
View attachment 24122

There is a large control box that joins the battery, charge controllers, inverter and other battery related stuff - where I have individual circuit breakers to disable each Midnite (DC in) and each Inverter (DC out) and the SACE shunt-trip to disable the battery itself (DC in). The SACE should be in the control box but I didn't have room. I've often disabled the Midnite circuit breakers at the control box to work on the battery/inverter system but left the PV input on at the Midnites - all with no trouble.
View attachment 24124View attachment 24123



One side affect of 'not' wiring in the charge controller DC input to the shunt-trip is that I can still have power coming in from the Midnite even with the battery off - so its important to flip the charge controller circuit breakers before digging in to see why the shunt-trip went off :)
Looks nice! 3 Midnights!! I am going to be using one that will be a lot more than needed for my meager array--but this is all temporary, just few more years.
I do plan on having everything with a manual breaker. I have just been searching through Amazon finding DC and AC breakers.
I am not sure I will use the center post to break the inverter, as if the solar charge controller is off, then that should shut down the output to the battery so no problem.
Once I get everything in this week, I will have to start mocking everything up to work out what fits where.
Thanks for the help
 
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