# Running positive and negative in same conduct?



## quinnbrian (Mar 6, 2014)

Hello all,
Can I run both my positive and negative leads in one conduit ,from my combiner box down to my Midnite Classic 150 charge controller? The reason I ask , is because , I would be running close to 70 amps @ 5200 watts from the combiner to my e-panel and didn't know if there would be any problems.
Thanks for any help.
Cheers
Brian


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## 8301 (Nov 29, 2014)

same conduit is fine and as a backup I'm using a breaker at the combiner box (out by the panels) which will protect if a short does occurs.

If you're running underground I'd suggest using 4 ga THHN wire designed for burial.

A lightening arrester in that line is also smart insurance. Finally,,, a reminder... you must have a clearly labeled cut off switch outside the house within 10' of where the wires go into the house per NEC whether you are grid tied or not. It's for firefighter safety.

You probably already know all of this but just a reminder.


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## quinnbrian (Mar 6, 2014)

Thanks FoolAml, 
I was just worried about heat build up in the conduct. The conduct is plastic. Wouldn't uses steel...and yes the main cut off switch is mandatory.Thanks for your quick reply.
Cheers
Brian


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## paraquack (Mar 1, 2013)

If there is a build up of heat, the wires are way too small.


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## 1skrewsloose (Jun 3, 2013)

There are restrictions on the size and amount of wire to run thru a certain size conduit based on amp draw. We have a book on it a work, I'll try to find. Goolgling may be easier, and faster!! Off the top of my head I couldn't tell you what size wire or conduit to use. Go big when in doubt!


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## dwight55 (Nov 9, 2012)

Your amp capacity can be determined by this NEC chart: Lapp Online Catalog: Appendix- National Electrical Code

The numbers of conductors per conduit can be found here: Conduit Fill Chart

Basically, you need # 4 wire in a 1 inch conduit if I were doing it.

I am curious though, . . . you said 70 amps @ 5200 watts. That works out at 75 volts. What kind of system are you running?

May God bless,
Dwight


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## tango (Apr 12, 2013)

You can run both in the same conduit as long as they are insulated from each other.


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## quinnbrian (Mar 6, 2014)

dwight55 said:


> Your amp capacity can be determined by this NEC chart: Lapp Online Catalog: Appendix- National Electrical Code
> 
> The numbers of conductors per conduit can be found here: Conduit Fill Chart
> 
> ...


16x325 watt mono-crystalline for my house. Running a Midnite Classic 150 ,a Magnum 4400watt 48 volt inverter and 16 x 6 volt batteries. I have alot of solar panels, but got a great deal and had to take them all (16).
I think I'm going to just try 8 panels at first and see how far I get. I'm in Canada ,so about 3 hour of good sun light a day ,in the winter months.
What do you guys think....I've been off grid for almost 4 years and the solar set up , is a big step for me.
Before the solar set up , I charged my batteries with a generator every other day ( in the winter) and every 3 days in the summer months.
Thanks again for all the help.
Brian


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## bigwheel (Sep 22, 2014)

We love Aggies over here.


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## quinnbrian (Mar 6, 2014)

:armata_PDT_36:


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## bigwheel (Sep 22, 2014)

Canada..eh? Parley voo..francois?


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## paraquack (Mar 1, 2013)

Depending on the type of cable you use, you should have at least a number 1 copper wire, I think you could get away with number 3 THHN copper wire. You'd need 1" or larger conduit.


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## quinnbrian (Mar 6, 2014)

bigwheel said:


> Canada..eh? Parley voo..francois?


No I don't speak French......I'm from the other Canada...LOL...Ontario


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