diy solar

diy solar

Combiner and Breaker for 250vdc

MrM1

I'm Here, But I'm Not All There
Joined
Mar 1, 2021
Messages
2,421
Location
N. Central FL
We have kicked around over paneling the Growatt 12kw 250vdc and it seems from many discussions, that it is not advisable. Might could get away with maybe 20% over, but in the end we decided it is not worth it, so we decided to just add a second 250v SCC.

I had found an 8 string input, 2 output combiner from Watts247 that is rated for in excess of 250v, but now we need the 4 - 2 combiner to go with our 8 - 2 so that we can add the second SCC. The inverter AIO and the new external SCC will both have 2 PV inputs each: PV1 and PV2. So we will build out 4 seperated 4s2p arrays using 370w panels with a VOC of 47.46v per panel.

Problem is I am having a hard time locating another combiner that is rated for 250vdc. Watts247's 4 - 2 is out of stock. I could use a pair of Midnite solar 3 breaker boxes but from what I can see the breakers are only good for 150vdc. I think I understand that you can parallel them, but really do not want to do that.

What are my options for a 250vdc combiner box? Will I have to use fuses instead of breakers?
 
MidNite Solar MNPV combiner boxes can be fitted with 150 volt, or 300 volt breakers or finger safe fuses in the same voltages. the 300 volt breakers are double gang breakers wired in series but they are Listed to UL by ETL or UL, MidNite uses both testing labs to list products.
 
We have kicked around over paneling the Growatt 12kw 250vdc and it seems from many discussions, that it is not advisable. Might could get away with maybe 20% over, but in the end we decided it is not worth it, so we decided to just add a second 250v SCC.

I had found an 8 string input, 2 output combiner from Watts247 that is rated for in excess of 250v, but now we need the 4 - 2 combiner to go with our 8 - 2 so that we can add the second SCC. The inverter AIO and the new external SCC will both have 2 PV inputs each: PV1 and PV2. So we will build out 4 seperated 4s2p arrays using 370w panels with a VOC of 47.46v per panel.

Problem is I am having a hard time locating another combiner that is rated for 250vdc. Watts247's 4 - 2 is out of stock. I could use a pair of Midnite solar 3 breaker boxes but from what I can see the breakers are only good for 150vdc. I think I understand that you can parallel them, but really do not want to do that.

What are my options for a 250vdc combiner box? Will I have to use fuses instead of breakers?
would this help.. its square d breakers 250 v dc
they make several
 
Last edited:
would this help.. its square d breakers 250 v dc
they make several
Wait a minute here...

IT IS NOT RATED 250 volts DC..........Its a 2 pole 50 amp breaker rated 240 volts AC and 48 volts DC

Square D division makes all QO line breakers rated 120 volts AC and 48 volts DC for each breaker, a 2 pole breaker is rated 240 volts AC

Square D is a division of Schneider Electric Company

DISCLOSURE.....Im a commercial Electrician who is a Square D and Schneider Electric stocking installer....

Please refer to Square D catalog and specifications sheets....
 
Midnight Solar MNEPV Combiners use CBI....Circuit Breaker International breakers which are certified to 120 volts DC in Africa and are recertified as 150 volts DC by U.L.

Midnight MNDC Breaker panels use Carlingswitch breakers which are certified by Carlingswitch for AC or DC,
midnight does not recertify Carlingswitch breakers
 
Back
Top