Powering a shed 250' away

[rpdwyer]

Hi all.

I’m looking to power a shed about 250’ feet from my house panel via a buried PVC conduit.

Lowes sells Southwire 8/3 Stranded UF Wire with ground by the foot. Is this wire sufficient for PVC conduit burial up to 250’, 2 legs each sending 120V paired to a double throw 30 Amp breaker in my main panel?

Thank you.
--Rick

 

[wwhitney]

Because of the length, you want to check voltage drop. And that is best done by estimating the actual current drawn, not the size of the breakers. So what are the actual loads you want to power, and their respective operating currents?

If you are running buried PVC conduit, it generally doesn't make sense to pull a cable inside of it; instead pull individual conductors.

Cheers, Wayne

 

[Sponsor]

 

[rpdwyer]

Because of the length, you want to check voltage drop. And that is best done by estimating the actual current drawn, not the size of the breakers. So what are the actual loads you want to power, and their respective operating currents?

If you are running buried PVC conduit, it generally doesn't make sense to pull a cable inside of it; instead pull individual conductors.

Cheers, Wayne

Thanks. If I want 30 Amps and 220V at the shed panel, it looks like to be under 5% voltage drop at around 230' (i can get it down to 230) I need two hot legs of 4 awg. Is it less expensive to run individual conductors or cable?

--Rick

 

[wwhitney]

If you are installing a complete PVC conduit run, individual conductors are generally less expensive, as are aluminum conductors. If you run a single cable inside conduit, you need to use the OD of the cable, and a circle of that diameter needs to be no more than 53% of the inside area of the conduit.

But unless you're powering a 7200W electric heater, it's unlikely that your actual current is 30A. It's overkill to use the full breaker rating for the voltage drop calculation, use the actual expected current, not the worst case.

Cheers, Wayne