Factory Solar wiring issue

[mrgrayaz]

2005 Alfa SYF30RLIK.

I recently bought a 400watt Renogy solar kit. I planned and purchased this kit planning on using the factory 12AWG wiring, and found both ends of it - one end in the battery compartment, the other sitting under the toliet vent cap. Nasty, stiff, and covered in black stuff, but there....

Hooked it all up...and....no voltage on the wires in the batt compartment. Clearly I have a wiring issue. I'm not asking for wiring help per se, I know how to wire, my connections are good. I get 85v out of the array and my soldered/crimpled connections are good. I sewing needled the factory wires post solar array connection and can see the voltage there.

So my question is this - has anyone seen a pre-built in fuse or perhaps a switch on factory wiring? I'd assume it was simply two wires, run one end to the other, but who knows...

[mrgrayaz]

So I figured this one out myself by spending some time tracing wires - it was really stupid. Ready?

I traced the pre-installed wires from the roof all the way down vent pipe into through the wiring "closet". The wires were white and red and 10AWG.

The wires I tied into in the battery box labeled "SOLAR WIRING" were white and black, and 12AWG.

I found the white and red wires ALSO sitting in the battery box unlabeled, and sure enough, had my 85V of Solar power in it.

Good job Alfa!

[cruzbill]

Good job! Now, are the 12ga pair supposed to go to the monitoring panel from the solar controller? Or??

[Dranoel]

If possible, consider replacing the 12AWG with 6AWG. You will lose much less power between the array and the batteries. I installed a 600W Renogy array on our rig.

[mrgrayaz]

Originally Posted by Dranoel

If possible, consider replacing the 12AWG with 6AWG. You will lose much less power between the array and the batteries. I installed a 600W Renogy array on our rig.

Hi Dranoel,
thanks for the reply.

It all depends how you set it up - I'm running a Renogy kit as well. The Rover MPPT with 4 panels in series with an array voltage of ~75V @ 6amps or so......10awg @25 feet is just fine for 6amps:

Voltage drop in volts:
0.298V

Percentage of voltage drop:
0.393%

though let me tell you, buzzing yourself with 76V DC is not fun lol!

There are many series vs parallel arguments, but this kit was setup for series and it seems to be working well.

The Rover tops out at 520watts or 100V....the voltage limitation would cause me trouble over 500watt (5 panels) all in series.

What Renogy kit are you using? I thought the 400watt was a very good value for money (About $1watt + controller and wiring) but the limitation at 500watts bugs me a bit.

Mike

[Dranoel]

Yeah Mike, in series you'll do fine! Mine was not a kit. Bought the panels, mounts and wire from Renogy. Morningstar 45 MPPT, combiner box, breaker et al from others. My understanding is that MPPT controllers simply discard power above their max. They are not damaged by it. Check it though :-) . My panels are in three strings series/parallel.

[mrgrayaz]

Originally Posted by Dranoel

Yeah Mike, in series you'll do fine! Mine was not a kit. Bought the panels, mounts and wire from Renogy. Morningstar 45 MPPT, combiner box, breaker et al from others. My understanding is that MPPT controllers simply discard power above their max. They are not damaged by it. Check it though :-) . My panels are in three strings series/parallel.

I'm up to 600watt so far . Never seen the controller hit 40amps, though close @36 amps.

Thanks for giving me a bit of confidence with adding panels there!

[Dranoel]

Congratulations Mike! I've not hit 40 amps often. You'll need to be far south in late June with a clear sky! :-)