Do I need a combiner box?

[Wv lew]

Hello all. If I put 6 panels in series (Trina 280 watt), then put Two of these 6 panel series (for a total of 12 solar panels in parallel, do I need a combiner box or can I just wire them at the ground mount? See attached. I may add on in the future and will likely add on. I already ordered a midnight solar fuse 15 amp and PV disconnect.

 

[Pappion]

3 or more strings in parallel should have each string fused. MC4 fuse holder is the easiest way to do this.
Issue: One string shorted will have 2 strings dumping current into it. May exceed wire rating.
example MC4 fuse holder

 

[rodrick]

With only 2 strings you can use a branch connector no box needed

 

[OffGridInTheCity]

Agree with @rodrick that with only 2 strings (<25a on the wire) the 10awg PV wire is fine. However, there are additional reasons for a combiner box (or just a box on the outside) you may want to consider
1) Quick Disconnect on the outside within 10ft or so of the array. Some jurisdictions require this and it's not a bad idea from a practical standpoint.
2) Lightning Arrestor (surge protection) before entering the home. Here's just one example - https://www.altestore.com/store/enc...lar-solar-surge-protection-device-600v-p9043/

Don't want to come off as critical of you're plans - just wanted to bring these topics up for you're consideration.

 

[efficientPV]

How does 12 panels turn into 22

 

[1201]

Hello all. If I put 6 panels in series (Trina 280 watt), then put Two of these 6 panel series (for a total of 22 solar panels in parallel, do I need a combiner box or can I just wire them at the ground mount? See attached. I may add on in the future and will likely add on. I already ordered a midnight solar fuse 15 amp and PV disconnect.

hi , sorry im of no help just have a question - what ground mount kit is that? thanks

 

[rodrick]

How does 12 panels turn into 22

Large fingers and small keyboard?

 

[Wv lew]

How does 12 panels turn into 22

22? I have 12 total, 6 in series in parallel with another 6 in series. I just reread it and see I fat fingered that should say 12, total I will
Correct.

 

[timselectric]

No fuses or combiner box are required. For that setup.
But, you can use one if you want. For the other benefits.

 

[Wv lew]

Agree with @rodrick that with only 2 strings (<25a on the wire) the 10awg PV wire is fine. However, there are additional reasons for a combiner box (or just a box on the outside) you may want to consider
1) Quick Disconnect on the outside within 10ft or so of the array. Some jurisdictions require this and it's not a bad idea from a practical standpoint.
2) Lightning Arrestor (surge protection) before entering the home. Here's just one example - https://www.invertersupply.com/index.php

Don't want to come off as critical of you're plans - just wanted to bring these topics up for you're consideration.

The link just takes me to a
General site. Thanks

 

[Wv lew]

hi , sorry im of no help just have a question - what ground mount kit is that? thanks

It’s one I put together with unistrut. It is a work in progress. I can put something together if you’d like. It sagged a little which is why it’s a work in progress. Super strut (unistrut is amazing).

 

[Wv lew]

Hello all. If I put 6 panels in series (Trina 280 watt), then put Two of these 6 panel series (for a total of 12 solar panels in parallel, do I need a combiner box or can I just wire them at the ground mount? See attached. I may add on in the future and will likely add on. I already ordered a midnight solar fuse 15 amp and PV disconnect.

Replying to my own post so hopefully people can respond that have so far. What combiner box is recommended? I would like reasonable price but quality for outside etc. thanks very much for your help. I think I’d like the breaker and fuse and surge protection so it makes sense.

 

[1201]

It’s one I put together with unistrut. It is a work in progress. I can put something together if you’d like. It says a little which is why it’s a work in progress. Super strut (unistrut is amazing).

its looks very nice. did you make or buy the posts?

 

[OffGridInTheCity]

The link just takes me to a
General site. Thanks

Thank you - corrected in post above. Trying to point to Midnite Solar''s surge protection device as an example as this is what I use - https://www.altestore.com/store/enc...lar-solar-surge-protection-device-600v-p9043/ - but there are others.

 

[Mattb4]

Replying to my own post so hopefully people can respond that have so far. What combiner box is recommended? I would like reasonable price but quality for outside etc. thanks very much for your help. I think I’d like the breaker and fuse and surge protection so it makes sense.

You can find find several combiner boxes on Amazon. Many are reasonable price but in regards to quality the biggest issue you should be aware of is to watch what is inside them. Some will have inadequate fusing, some will have inadequate wire size for the application. However the concern you need to take care of is that often the various connections inside may not be properly tightened. It seems that quality control these days is not a priority.

Avoid MC4 inline fuses if at all possible unless you buy Staubli brand.

 

[Wv lew]

its looks very nice. did you make or buy the posts?

Bought. Eco worthy. I poured concrete and modified. Otherwise you can barely
Get any solar panels on it.

 

[Wv lew]

Thank you - corrected in post above. Trying to point to Midnite Solar''s surge protection device as an example as this is what I use - https://www.altestore.com/store/enc...lar-solar-surge-protection-device-600v-p9043/ - but there are others.

Thank you

its looks very nice. did you make or buy the posts?

thank you.

 

[Wv lew]

Hello all. If I put 6 panels in series (Trina 280 watt), then put Two of these 6 panel series (for a total of 12 solar panels in parallel, do I need a combiner box or can I just wire them at the ground mount? See attached. I may add on in the future and will likely add on. I already ordered a midnight solar fuse 15 amp and PV disconnect.

Replying to my own post so anyone in this group can see/respond. This is what I ended up with on my first 12 panels. I have 30 more on the way, of which I’m going to mount 24, and thinking of using the other 6 for a solar mini split.

For the record I bought the eco mounts and modified them a bunch.

 

[Hogheavenfarm]

Be aware those plastic combiner boxes can leak as the plastic warps slightly in the heat. I had to put a small roof over mine. I know they are supposed to be "waterproof", but mine wasn't.

 

[Wv lew]

Be aware those plastic combiner boxes can leak as the plastic warps slightly in the heat. I had to put a small roof over mine. I know they are supposed to be "waterproof", but mine wasn't.

Good to know. I may go ahead and put something over it as a precaution.