it's all in the connections

[BackTOschool]

I'm nearly there... advice please:

My system:
2S4P, each string has 2 x 330w panels, each panel output is: 32.6v (VMP), 10.2 (IMP), & 10.9 (ISC). this gives a max output of 2640w to the charge controller.

QUESTION:
1: Do I HAVE to use a combiner box, or could I use the standard mc4 connectors to the charge controller instead?
2: If I HAVE to use a combiner box, the ones I've seen available all seem to be limited on the max watts (much lower than 2640) for 12 volt systems? ( confusion alert: my panels are rated at 32.6v output - not sure if that is relevant or irrelevant?)
to be honest I'm a bit confused right now, advice please?
kind regards
Steve

 

[SamDeleted]

I'm nearly there... advice please:

My system:
2S4P, each string has 2 x 330w panels, each panel output is: 32.6v (VMP), 10.2 (IMP), & 10.9 (ISC). this gives a max output of 2640w to the charge controller.

QUESTION:
1: Do I HAVE to use a combiner box, or could I use the standard mc4 connectors to the charge controller instead?
2: If I HAVE to use a combiner box, the ones I've seen available all seem to be limited on the max watts (much lower than 2640) for 12 volt systems? ( confusion alert: my panels are rated at 32.6v output - not sure if that is relevant or irrelevant?)
to be honest I'm a bit confused right now, advice please?
kind regards
Steve

You can't use MC4 combiners because mc4 are 30amp max , you'll be over 40amps with that setup

But you don't have to use a combiner box, there are other options, high amp block connectors come to mind

Also either way you will need some kind of fuse / circuit breaker on each string , probably 20amp

 

[SamDeleted]

These Henley's are a good option for block connectors if you're in the UK ??

100 amp Henley block RDL 5 Port up to 25mm tails Junction Joint box | eBay

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[MichaelK]

I don't know where you are looking, but the combiners I'm used to are rated for volts, not watts. I'm using Midnight. In the US, either a breaker or fuses are a REQUIREMENT for three or more parallel strings. So, you don't HAVE to use a combiner, but it makes your life much easier.

Are you actually trying to build this as a 12V system? If you are, 2640W is far too many watts for 12V. Even with 85% derating, you might be presenting (2640W/13Vcharging) X 85% = 172.6A to your charge controller. Far more than what the typical high-capacity controller is designed for. This would be still quite large, though doable, for a 24V system. Even at 24V, you'd need 2 gauge copper wire to safely transmit that much amperage. This level is starting to enter 48V territory.

So, what exactly are you attempting to build here? I think it would be wise at this point to put a halt on things, until a complete plan is fleshed out. Right now, what you are talking about appears very imbalanced.