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Steve avatar image

fuse/circuit breaker between panel and controller ,do i need one

hi,200w solar panel to victron 75/15 mppt controller,do i need fuse or circuit breaker inbetween,if so what size,been running a 100w for over a year with nothing inbetween thanks steve

fuse
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2 Answers
Elimac avatar image
Elimac answered ·

Its kind of mandatory to have a fuse in series with each string of solar panels that are in parallel. It's more because of the panels than the controller.

In case you only have one string or individual panel as it seems to be your case, you could be ok without a fuse, but I would recommend it anyway too. It's always good practice. And the currents are not that high, so the losses are minimal. Beware however of good crimping/ contact. The fuse should be a little higher than the Isc of the panel. Normally the panel datasheet states the maximum value for this fuse. I use 15A for my panels with 9A Isc.

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thank you for your help

mobile-rv30 avatar image
mobile-rv30 answered ·

Can people give some guidance on the Circuit Breaker ratings on this proposed schematic please ?

4 x 350 Watt Panels , 2P x 2S
Victron 100 / 50 mppt
4 x 6 V / 440 AH AGM batteries in series.
Victron Multi 24/3000 inverter.

Should i have a CB on each Solar String , and what is the correct size per 2 panels in series ?

Are my ratings correct for the other parts of the circuit ?

My cables are 6 mm sq for the 9 metre run from panels to mppt , 65 mm sq cable for batteries to Multi 24/3000.

Yes i will have an electrician doing the connections but i already have lots of CB's in stock and want to pull the cables and mount the breakers before he arrives.

solar-circuit-breaker-sizing.png


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