Solar input circuit breaker

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RJJ

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Hi

We have 320w of solar with a regulator rated for 350w. The regulator instructions recommend a 30A circuit breaker between the reg and the battery.

A couple of days ago the breaker tripped. By my maths, the panels cannot generate more than 26A and that would assume 100pc.efficiency. so what gives, and is it a problem?

Anyway, they have been working a peach for the last couple of days. I guess it's a reminder to check the batteries are in fact charging when I think they are charging. I was down to 50pc and it's taken two days to get back to full charge.

Thanks.
 
My panels regularly exceed 100% rated capacity. Uprate the cable and uprate the breaker to match. 6mm cable is rated to 50A and I assume you have at least that installed?
 
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lustyd said:
My panels regularly exceed 100% rated capacity. Uprate the cable and uprate the breaker to match. 6mm cable is rated to 50A and I assume you have at least that installed?
Click to expand...
Can't recall the size. But I'll work on it! V boring if they trip out all the time.
 
lustyd said:
My panels regularly exceed 100% rated capacity. Uprate the cable and uprate the breaker to match. 6mm cable is rated to 50A and I assume you have at least that installed?
Click to expand...

Which panels are those? ... mine have never exceeded 100% rated capacity in the 2-3 years I`ve had them ......

I have 300W panels (3 x 100W) in series and the most I see out of them is around 270W - and that's quite rare - they usually deliver around 200-230W in good conditions. I have a Victron 100-30 and its records show a max solar voltage of high 60s up to around 70v with solar current around 3A .... output is usually 10-15A to the batteries.

If I put them in parallel I'd still only see around 9-10A on the solar side.
 
My domestic roof panels are rated at 3.68kW and I have seen them produce 4.25kW. The panel output specification is under standard conditions of 1kW/m2 of solar irradiation. I think you would be unlikely to exceed 1kW/m2 on my location in the south of UK so I can only assume that some manufacturers are conservative in their ratings. It's a bonus for me as the projected annual output of 3555kWh is always above 4000kWh and I am on the maximum FIT.
 
Fwiw, 2x300w on the hard top, no mast to shadow them, still rarely seen over 550. This v.v.hot summer only seen 480w max for few mins. Mind efficiency drops with temp so with ambient on the 20s and strong sunshine you could reach or theoretically exceed rated output...

V
 
Baggywrinkle said:
Which panels are those? ... mine have never exceeded 100% rated capacity in the 2-3 years I`ve had them ......

I have 300W panels (3 x 100W) in series and the most I see out of them is around 270W - and that's quite rare - they usually deliver around 200-230W in good conditions. I have a Victron 100-30 and its records show a max solar voltage of high 60s up to around 70v with solar current around 3A .... output is usually 10-15A to the batteries.

If I put them in parallel I'd still only see around 9-10A on the solar side.
Click to expand...

Looking back at the Victron MPPT log for my 200W of solar i see a few days of over 200W, the most being 224W.

10-15A going to the batteries isn't a lot for 300W, i had up to 13.88A today, for instance.
 
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