My choice of wiring

D

Dmcbudman

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Oct 12, 2018
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So I put a few panels on my garage and need to wire them to my house.
I currently have electric (10/3 I think) running out there, but it was never hooked up as long as I've been here. So I connected my solar, but when I checked voltage on the other side all I got was 0.5v (guess there's a reason it was unused). Tried pulling the old wire through, but that's wasn't happening.
Anyways I need new wiring ran but can't dig a new trench, so I need to go aerial... Tomorrow I am running rg6 and running power through that.
Bad idea?
I have the dual coax like for satellite. Going to do one positive and one negative, cause screw trying to use that little center piece of copper alone.
As far as I know rg6 can handle a few hundred volts, but I don't have a clue about voltage drop (only a 50-75 feet run)
If I shouldn't do it, please speak up :)

-D
 
Hi DMC. I'm speaking up... Don't do it!

RG6 is designed for low voltage and low current.

It would probably handle decent enough voltage, but its the current that would burn it out very quickly. In fact, it is often use to power masthead amps in Antenna systems up to 21v, and Satellite LNB at 18v.

Perhaps the reason you can't pull the old cable through is because a tree root has penetrated the pipe, and this would also be the cause of the voltage drop. I don't know what 10/3 is (assuming 10Amp 3 wire?). If its AC mains, once again... not designed for the high DC currents possible off solar panels. What is 'a few' panels?

Do some impedance testing between the 3 and each end to work out whats going on - what's broken and what's shorted. A cable tester could even tell you where the break is, so you could then pot hole to find the problem.

Where are you located?
 
RG6 is shielded, so the volts and heat cannot escape. Perfect for high current, long distance runs.
 
Oops guess a few specifics would have helped.
It's just 4 100w panels, haven't decided on 2p or 4p yet though.
10/3 was ac 10 gauge 3 strand. I didn't really want to use that, if I had to it was only going to be a 20 foot or so section of the run... So not really worth the effort to repair it.

Are you suggesting I just use the coax as 'intended' use the inner conductor for positive and the shielding for negative?
 
A common standard is PV specific(red/black, outdoor/ultraviolet-protected)10awg wire. The 10awg is not so important (current/length) in your case. Panels typically have MC4 connectors which PV specific 10awg fits nicely into (not sure if that's your situation).
 
10/3 romex is 10ga two conductor, neutral ,plus ground, split phase 110/240 . Unless the wire is 10/2 which is 0ne hot wire, one neutral plus a ground.
Where are you trying to pull the wire from? The service or the garage?
Check for junction boxes / wire nuts will stop the wire from being pulled. Any 90s can also be a problem. simply a loose wire nut could explain the 0.5v reading.

later floyd
 
Well I guess it's not 10/3, 10/2 is more like it. Not to familiar sorry. It's not standard Romex though, black/white/red all insulated.
Yeah I was physically yanking it in an attempt to fish something else through, as it's disconnected on both ends. But you called it, there's a 90 turn at the garage floor plate.
I can give it another go if you really think that would be better than the rg6... Maybe I can put an inverter in the garage and run that to the house.
That's getting into to much though, the rg6 would be a lot easier lol
 
How old is the garage?
The colors of the wiring is for two hots black and red wires and a neutral white wire. Someone who is more knowledgeable on wiring might be able to tell you if it is for a sub panel with both legs of the 240v service. Would make sense garages often had the laundry room in them and 240v is required for most electric dryers.


Later floyd
 
slimf said:
RG6 is shielded, so the volts and heat cannot escape. Perfect for high current, long distance runs.
Click to expand...
I hope you're not serious in suggesting this is viable for high current? You are right... the heat won't escape and you'd be left with a hot sticky mess.

Not knowing the specs of your 100W panels, I'm figuring in series you might be OK to use the RG6. It'd probably handle a few amps but that's as far as I would push it. In series means higher voltage, and lower current, which it would handle better. Not something for a long term plan though.

Note that Fig.8 DC cable used for solar is generally the same size as 2 RG6 and its ALL copper! No dielectric between centre and shield.
 
[quote="Wayne']
slimf said:
RG6 is shielded, so the volts and heat cannot escape. Perfect for high current, long distance runs.
Click to expand...
I hope you're not serious in suggesting this is viable for high current? You are right... the heat won't escape and you'd be left with a hot sticky mess.

Not knowing the specs of your 100W panels, I'm figuring in series you might be OK to use the RG6. It'd probably handle a few amps but that's as far as I would push it. In series means higher voltage, and lower current, which it would handle better. Not something for a long term plan though.

Note that Fig.8 DC cable used for solar is generally the same size as 2 RG6 and its ALL copper! No dielectric between centre and shield.
[/quote]

RG6 is good For at least 500amps :p
 
slimf said:
RG6 is good For at least 500amps :p
Click to expand...

Can you provide a link to said information please? I did a search and i can't find ampacity ratings for coax cable. I find it for Vmax, though. Which, for RG6 braided Vmax is 2700V
 
Korishan said:
slimf said:
RG6 is good For at least 500amps :p
Click to expand...

Can you provide a link to said information please? I did a search and i can't find ampacity ratings for coax cable. I find it for Vmax, though. Which, for RG6 braided Vmax is 2700V
Click to expand...

Im joking. RG6 is not designed for power.
 
Figured I'd take it slow, only hooked up 2 in series. I'll parallel the other 2 when I know it's safe. But under 400w I'm sure it will be.
Don't have a meter on both ends but it looked better than 95% at the controller. somewhere around 1v drop over 50' (75' was too much)
 
If RG6 is all the cable you have then...
Center core for RG6 is 1mm2 or good for about 10A in thoery. Also depends if it's solid core or air gapped.
Use the outer AND inner together if your running 2 wires, just use one wire as +ve and the other -ve.
Solid core RG6 you can "play" with with quite a few kV as long as you don't mind the odd random fire and blinding light incident.

Not ideal, recommended or electrically approved in any way but will work.

Caution on the outer insulation layer as depending on the cable (internal or external rating for UV as well) they can be softer and easier to cut accidentally. Water ingress then get's sucked into the outer braiding quite eaisly through capilary action and corrodes it (with the help of those electrons).
 
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