Which Combiner box?

pda1

Solar Enthusiast
Joined
Feb 16, 2021
Messages
111
I'm at the point of selecting a combiner box but don't know which one or size to get.
My soon to be system will have 4 panels- 2s2p (each panel is about 250watts- each of the panels specs to about 38Voc and 9 Isc). The MPPT is a Victron 150/60.

However, at a later date I'd like to add 2 more panels and arrange them with the previously mentioned 4 as 3s2p.

So, I'd like to get a combiner box that can handle those inputs and have a breakers (fuses) built into the box along with a disconnect. Ecoworthy boxes look good.

What do you think?

Thanks
 

740GLE

Solar Addict
Joined
Apr 30, 2021
Messages
641
Midnite solar look like quality units

MNPV4 Would allow for future expansion if needed.
 

chrisski

Solar Boondocker
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Aug 14, 2020
Messages
2,692
You can read the specs for the Y cables. I use those so much easier to setup. I only have 2P, but I fuse each string. I also have the midnight solar combiner box for 3S2P with 600 watts total. Its mode for so much more than 600 watts. I also made a combiner box for half the price of the Midnite solar, but not the same quality.
 

pda1

Solar Enthusiast
Joined
Feb 16, 2021
Messages
111
'Was wondering about those Y cables. Thanks for the ideas.
 

chrisski

Solar Boondocker
Joined
Aug 14, 2020
Messages
2,692
With Y Cables, the MC4 connection will limit it to 30 amps, but the volts I’m not sure about. WIth 3S in a 250 watt panel, I suspect you could reach 100 volts. The specs for the Y cable would say max voltage. I’ve noticed panels are not often desifned to produce more than 10 amps, at that point, volts go up.

For two strings, you may not need fusing. For me, I have fusing on each string and an additional circuit breaker to shut the main feed off after its combined. THe circuit breaker helps for troubleshooting and when I want to limit PV input while in storage.
 

740GLE

Solar Addict
Joined
Apr 30, 2021
Messages
641
Insulation class of *quality* MC4 connectors is well above 100v.

All depends on what brand and what they rate their product for.

My vote for a combiner box is for ease of trouble shooing issues with a string, no need to monkey with connectors when you can just open a breaker.
 
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