Wire Type and Sizing Inverter to Breaker

[DrZ123]

I am moving my inverter and batteries to a power shed to free up room in my off grid home. I have a Victron Quattro 5000w/48v inverter and 1600w of panels. 8x 48v 100ah batteries.

Currently the inverter is about 10ft from the breaker panel and wired using 3x 4awg cables for line, neutral and ground.

In the new setup, the inverter will be around 50 feet from the panel, and in a shed so I need to run wires outside, exposed (house is on a rock island). What is the best wiring to use that is both capable of carrying the load as well as resistant to rain, saltwater spray, etc of being outdoors?

Thanks!

 

[wpns]

What is the best wiring to use that is both capable of carrying the load as well as resistant to rain, saltwater spray, etc of being outdoors?

Wire in conduit.

 

[DrZ123]

So you would use the same 4awg cable using grey rubber conduit?

 

[SparkyJJO]

Yeah. I'd rather not have the cable exposed to sun. You could get SE cable I guess that's rated for it.

You have a loose ground btw (lower right in your panel).

 

[wpns]

So you would use the same 4awg cable using grey rubber conduit?

Well, 4AWG should be fine as per https://www.calculator.net/voltage-...stanceunit=feet&eres=20&x=Calculate&ctype=nec
But flex (‘liquidtight’) is really hard to pull wire through, I’d recommend solid PVC conduit

 

[DrZ123]

Well, 4AWG should be fine as per https://www.calculator.net/voltage-...stanceunit=feet&eres=20&x=Calculate&ctype=nec
But flex (‘liquidtight’) is really hard to pull wire through, I’d recommend solid PVC conduit

I think solid PVC is going to be hard as there are alot of ups and downs on rock and under the house. For the conduit, and 3x 4awg cables plus the solar panel cables, what size is recommended? 1" conduit?

 

[wpns]

I think solid PVC is going to be hard as there are alot of ups and downs on rock and under the house. For the conduit, and 3x 4awg cables plus the solar panel cables, what size is recommended? 1" conduit?

Hmm, AC and DC should really go in separate conduit for safety reasons, even if you don’t care about code.
Talk to your electrician about what conduit sizes he recommends. I suppose it’s possible to use liquid tight if you use plenty of lubricant, But I have issues with liquid tight at more than five or 10 feet, much less 50.

 

[DrZ123]

Hmm, AC and DC should really go in separate conduit for safety reasons, even if you don’t care about code.
Talk to your electrician about what conduit sizes he recommends. I suppose it’s possible to use liquid tight if you use plenty of lubricant, But I have issues with liquid tight at more than five or 10 feet, much less 50.

Does the DC from the panels need to be in a conduit or can just run along the ground?

 

[SparkyJJO]

I'd put in conduit to protect them, whether or not it is considered mandatory.
Definitely keep them in a separate conduit from the AC.

 

[DrZ123]

This should work in the conduit yes?

Amazon.com

 

[wpns]

Does the DC from the panels need to be in a conduit or can just run along the ground?

Put any wire that’s running across the surface (especially of rocks and rocky ground) in conduit.

 

[wpns]

This should work in the conduit yes?

Amazon.com

Well, sure, but at least check out https://www.wireandcableyourway.com/ and get unbroken single wires for your runs

 

[DrZ123]

Worth running 3 individual wires or a single bundled wire through the conduit?

 

[wpns]

Worth running 3 individual wires or a single bundled wire through the conduit?

Doesn’t matter, whatever’s easiest or cheapest

 

[glandpuck]

THWN fine stranded in conduit. In your conduit run the +, - and any ground wire. At battery side have your fuse and at inverter side your battery breaker. As for the gauge, this will depend on the maximum charge and discharge amps your inverter is rated for plus a little extra for the length of the wire. So if inverter is limited to 150 amps charge and discharge from batteries, then a 2/0 should do it.
As a reference, you can run 3/0 +,- and a ground through a 1.5 inch conduit.

 

[DIYrich]

Use RMC, not EMT, outside, especially across rocks.
At a minimum THWN ("W" meaning water resistant, which you need for outdoors).
Consider UFWG wire, which is like Romex, but rated for Direct Burial. Romex can't be used outside, even in conduit, unless rated for Water.

For a 15 foot run, I ended up with UFWG inside RMC so I could bury as shallow as 6 inches. I could have used THWN inside the RMC.

 

[wpns]

Use RMC, not EMT, outside, especially across rocks.

The OP wants to keep this simple, would flexible (liquidtight) or pvc work from a safety perspective? It doesn’t sound like he cares about code.

 

[SparkyJJO]

THWN fine stranded in conduit. In your conduit run the +, - and any ground wire. At battery side have your fuse and at inverter side your battery breaker. As for the gauge, this will depend on the maximum charge and discharge amps your inverter is rated for plus a little extra for the length of the wire. So if inverter is limited to 150 amps charge and discharge from batteries, then a 2/0 should do it.
As a reference, you can run 3/0 +,- and a ground through a 1.5 inch conduit.

Where do you find this THWN "fine stranded" wire? I see two options - solid or stranded. No options as to how fine the strands are.

 

[wpns]

Where do you find this THWN "fine stranded" wire? I see two options - solid or stranded. No options as to how fine the strands are.

Welding cable?

 

[dougbert]

This should work in the conduit yes?

Amazon.com

that is $2.55 per foot

I have found nassau national cable as a good source for me

here for $1.39 per foot plus some $30 for shipping

4 THHN THWN-2 Stranded Copper Building Wire

Specifications : Size AWG : 4, Weight per 1,000 ft : 155 lbs, Outside Diameter : 0.330 inches, Conductors : Annealed Soft Copper per ASTM B3 and ASTM B8, Number of Strands : 19, Insulation : PVC, Insulation Thickness (mils) : 40, Nylon Thickness (mils) : 6, Jacket : PVC, Houston Wire Part # ...

nassaunationalcable.com

also here is a fill chart

Elliott Electric Supply - Lower Cost, Quality Electrical Supplies, and Personal Service

Electrical Supplies Distributor. Elliott Electric Supply is your local electric supply house. We Deliver Lower Cost, Quality Products, and Personal Service

www.elliottelectric.com

 

[SparkyJJO]

Welding cable?

Welding cable isn't THWN.

 

[dougbert]

I think solid PVC is going to be hard as there are alot of ups and downs on rock and under the house. For the conduit, and 3x 4awg cables plus the solar panel cables, what size is recommended? 1" conduit?

you probably need a couple of pull boxes if it is not straight

4 conductors max in 1",

I would go 1-1/4", max would be 7 in that

 

[DrZ123]

you probably need a couple of pull boxes if it is not straight

4 conductors max in 1",

I would go 1-1/4", max would be 7 in that

I should just need line, neutral, and ground so 3 cables total yes?

 

[dougbert]

I should just need line, neutral, and ground so 3 cables total yes?

are you 120v or 240v?

if 120v, then yes, just 3
if 240v or future 240v, then 4

 

[DrZ123]

are you 120v or 240v?

if 120v, then yes, just 3
if 240v or future 240v, then 4

Good point, I may add 240v later so I guess better to plan ahead!

What does a pull box accomplish?