diy solar

diy solar

Please help me think this through - A/C draining batteries overnight

z_zk_z said:
My Pioneer 9K BTU mini-split draws 800 watts and it seems running continuously lately during the day in Florida heat, so it would deplete a Signature Solar (5Kwh) battery in approximately six hours. I use this clamp on meter (https://www.amazon.com/dp/B07Z398YWF?psc=1&ref=ppx_yo2ov_dt_b_product_details) to see how much AC current it draws by clamping it in the circuit breaker panel. You are showing that you got "1740w PV solar panels". That is the ideal case. It doesn't appear that you got enough solar to keep your air-condition unit, the ref., and charge the battery, and your 24V/150ah battery is not much.
Click to expand...
I think I would need something to accumulate the hours consumed
 
I hope I found a cause for this problem. It appears that the 63 amp double pole breaker has failed after about a year or a little less of use. I checked the voltage on the input side coming in from the solar panels and it reads correctly at 77 V. The output voltage, that is to say the protected side of the breaker, there’s only 11 or 12 V whether or not the breaker is closed or open. I have ordered another to try to resolve the problem. I have four sunpower 435 panels each offering about 6 A hooked in parallel. My math shows a potential of 24 A which should be well below the 63 A of the breaker rating. I thinking is that the breaker has been failing slowly over time giving only partial current
 

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chrisstratton said:
I hope I found a cause for this problem. It appears that the 63 amp double pole breaker has failed after about a year or a little less of use. I checked the voltage on the input side coming in from the solar panels and it reads correctly at 77 V. The output voltage, that is to say the protected side of the breaker, there’s only 11 or 12 V whether or not the breaker is closed or open. I have ordered another to try to resolve the problem. I have four sunpower 435 panels each offering about 6 A hooked in parallel. My math shows a potential of 24 A which should be well below the 63 A of the breaker rating. I thinking is that the breaker has been failing slowly over time giving only partial current
Click to expand...

I don't trust no-name Chinese DC breakers. I only use reputable brands for protection devices.
 
chrisstratton said:
I hope I found a cause for this problem. It appears that the 63 amp double pole breaker has failed after about a year or a little less of use. I checked the voltage on the input side coming in from the solar panels and it reads correctly at 77 V. The output voltage, that is to say the protected side of the breaker, there’s only 11 or 12 V whether or not the breaker is closed or open. I have ordered another to try to resolve the problem. I have four sunpower 435 panels each offering about 6 A hooked in parallel. My math shows a potential of 24 A which should be well below the 63 A of the breaker rating. I thinking is that the breaker has been failing slowly over time giving only partial current
Click to expand...
Check the bottom left (black) lead
It looks like it's been getting hot and there's a good chance the connection is loose

I had a similar problem. The breaker tripped one day, reset and it was fine until the next day.
I swear I had the leads screwed down tight when originally wired but when I checked the second day of tripping I found one "not tight"
 
wiseacre said:
I found one "not tight"
Click to expand...
Agree with the "getting hot" brown spot as indicating trouble. I did put a screw driver on that lead/connection and it didn't move. The fact that I don't seem to get ANY voltage across the breaker was enough (that and the brown spot) were enough for me to order a replacement. When I put that new one in, I'll definitely check the tightness as well as look for corrosion. I remain hopeful that poor conduction across that device and the potential for random "partial failures" is the root of my problem. I haven't had to reset the breaker, but I believe they can fail w/o tripping.
 
chrisstratton said:
When I put that new one in, I'll definitely check the tightness as well as look for corrosion.
Click to expand...
I'd also check to see if the lead went into the fitting (whatever it's called)
When I replaced mine I inserted the wire behind the holder and tightened down.
One yoink later and it came out. Damn combiner box makes it impossible to see the bottom connections.

I suspect not seating the wire properly could have been my original problem but whatever it was it took almost two years to manifest
 
chrisstratton said:
Is there a brand you like? Amazon wasn't calling them up directly for me.
Click to expand...

Yes
If you're using 10awg wire the 30a will be ideal:

BTW I have 20 of those 435w sunpower panels. I have 5 on one of those 30a breakers, it once tripped on the 5. So 4 panels like you have will be perfect.

I'm reconfiguring mine so there will be 4 in parallel on each 10awg string with a 30a breaker each.
 
I only use molded case circuit breakers (MCCB); these miniature circuit breakers (MCB) are puny. Might be overkill, but it's just me.

Even with that, it's good practice to always check connections / terminations / temperature / ... (read: periodic maintenance check).
 
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