My truck camper has OEM wiring for a solar panel, the problem is that it's only 10awg wire. I don't really want to remove the fridge if i don't have to so I'm trying to figure out the best way to just use this wire. The run is about 8-10 ft to the charge controller.I am currently adding 2 12v 100w panels in parallel but have plans for 2 more.so the questions...1. how many amps can I get away with with the 10awg wire? Could I run them all in parallel or would the loss be too great?2. If I run them in series it seems like the voltage gets pretty high, most DC breakers and switches I've seen (using mostly blue sea stuff) has a maximum voltage of 48V. Do you start using AC breakers once the voltage gets higher?3. Maybe I could run two sets of parallel and then series them together?4. I realize that if I go series that I will need an mppt controller, Are the EP Solar controllers ok? I'd like a better one but it's cost prohibitive to get up here in Canada.Just trying to see if it's feasible to use the OEM 10 gauge wire.

Drop the wires DOWN from the removed cap, vent. I would go #6 AMERICAN WIRE GAUGE, not #6 SAE, size wire.Of course this is for paralleled connected panels and a PWM controller.

How well secured is the existing wire? If it's kind of loose, perhaps you can use it to pull new heavier wires down.Purely from a wiring safety point of view, you can go up to at least 30A and probably somewhat more with 10 AWG wire. Since the voltage drop is proportional to the current in the wire, you lose a lot less power by increasing the voltage where feasible.You should not use AC (only) breakers or switches for higher voltage DC circuits. AC switches and breakers are designed with the assumption that the voltage (and hence current) waveform will have zero crossings regularly, and hence any arcing have a "gap" and a chance for the ionized air to dissipate. DC switching is much harder on contacts than AC switching. Higher voltage DC circuit breakers are available, for example this 3 pole 10A 125 VDC breaker, or you could just use a plain old fuse and possibly a suitable switch or something (maybe a knife switch) since you presumably won't need to be disconnecting the solar panels frequently.

how many amps do those panels put out? isn't 30 amp adequate?bumpy

#10 is good for 40 amps if you are not concerned about voltage loss.I would have all four (same panels) in series to an MPPT controller.

Could you use 2 x 12 volt in parallel (double current), plus 2 x 12 volt in parallel, wired as 2 x 12 volt pairs, wired in series? Use a MPPT controller at 24 volts, with the 10 gauge running at 24 volts and only the amps of a a single pair in parallel?Single panel Amps * 4 / 2 pair in series = 2 x panel volts and 2 * panel amps.Please don't take any advise from me unless you check it yourself and take ownership of the idea......

Parallel vs Series, 10awg wire | Good Sam Community

27 Replies

hedge
Explorer
Jun 11, 2016
Thanks for the suggestions.

I've updated the post, 100w panels. I bought the Renogy kit so the controller that came with it is very basic so I plan to replace it anyways. I guess I'm just planning for a bit down the road.

I'm going to see how the 200w is first. We don't really use much power so it may be enough.

I'm just having a hard time seeing how they ran the wire, don't really want to break into the fridge screen if I don't have to.

At this point I think the Parallel + series is probably my best bet.
corvettekent
Explorer
Jun 11, 2016
How many watt panels are you planning to use?
I thing series parallel would be a great option but you would have 24 volts so you would need a MPPT controller.
The cheaper option would be to run new wire.
TNrob
Explorer
Jun 11, 2016
Could you use 2 x 12 volt in parallel (double current), plus 2 x 12 volt in parallel, wired as 2 x 12 volt pairs, wired in series? Use a MPPT controller at 24 volts, with the 10 gauge running at 24 volts and only the amps of a a single pair in parallel?

Single panel Amps * 4 / 2 pair in series = 2 x panel volts and 2 * panel amps.

Please don't take any advise from me unless you check it yourself and take ownership of the idea......
time2roll
Nomad
Jun 11, 2016
#10 is good for 40 amps if you are not concerned about voltage loss.
I would have all four (same panels) in series to an MPPT controller.
Bumpyroad
Explorer
Jun 11, 2016
how many amps do those panels put out? isn't 30 amp adequate?
bumpy
DrewE
Explorer II
Jun 11, 2016
How well secured is the existing wire? If it's kind of loose, perhaps you can use it to pull new heavier wires down.

Purely from a wiring safety point of view, you can go up to at least 30A and probably somewhat more with 10 AWG wire. Since the voltage drop is proportional to the current in the wire, you lose a lot less power by increasing the voltage where feasible.

You should not use AC (only) breakers or switches for higher voltage DC circuits. AC switches and breakers are designed with the assumption that the voltage (and hence current) waveform will have zero crossings regularly, and hence any arcing have a "gap" and a chance for the ionized air to dissipate. DC switching is much harder on contacts than AC switching. Higher voltage DC circuit breakers are available, for example this 3 pole 10A 125 VDC breaker, or you could just use a plain old fuse and possibly a suitable switch or something (maybe a knife switch) since you presumably won't need to be disconnecting the solar panels frequently.
MEXICOWANDERER
Explorer
Jun 11, 2016
Drop the wires DOWN from the removed cap, vent. I would go #6 AMERICAN WIRE GAUGE, not #6 SAE, size wire.

Of course this is for paralleled connected panels and a PWM controller.

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Parallel vs Series, 10awg wire

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