600ft voltage drop

[karn]

I'm installing an RV panel with 50, 30, and 20-amp receptacles inside the panel. However, the location of this panel is almost 600 feet from the house panel. I don't think 4 AWG copper will suffice due to voltage drop, and 2 AWG gets pricy fast, so I was considering using a direct burial cable such as UF-B, USE-2, or URD to save the customer some money. I just wanted to get another opinion.

 

[infinity]

What's the actual load on the panel and what's the voltage of the feeder?

 

[LarryFine]

Aluminum wire is less than copper wire for a given ampacity.

240v only with a 240-to-120/240v transformer saves a wire.

240-to-600v and 600-to-120/240v transformers reduce wire size.

 

[karn]

The load is a 5th wheel camper with a 50-amp shore power cord. I doubt the combined usage from the RV panel will ever exceed 50 amps. It uses a NEMA 14-50R receptacle.

 

[LarryFine]

He asked because actual voltage drop is dependent on actual load current (and circuit impedance, of course.)

 

[hillbilly1]

#2 mobile home feeder should be more than sufficient. A/C startup is the big issue with RV’s. If you’re still worried, 1/0 AL urd is not that much more.

 

[karn]

Yeah, I was thinking a 1-1-1-2 or even a 1-1-1-3, as there's 3 ac units on the RV

 

[ramsy]

Yeah, I was thinking a 1-1-1-2 or even a 1-1-1-3, as there's 3 ac units on the RV

That product is often found as a triplex with no EGC.

 

[karn]

For some reason I thought they had a 1-1-1-3 USE cable or a quadraplex, but it's been forever since I've used that stuff

 

[karn]

I usually install these RV panels using 6 AWG copper, or 4 AWG copper if they are over 100', in 1" EMT or 1.25" PVC, but I've never installed one this far away from the house before, and I wanted to give the customer a couple options to save them some money

 

[LarryFine]

Is overhead an option?

 

[Little Bill]

I usually install these RV panels using 6 AWG copper, or 4 AWG copper if they are over 100', in 1" EMT or 1.25" PVC, but I've never installed one this far away from the house before, and I wanted to give the customer a couple options to save them some money

Get the 2-2-4-6 mobile home feeder. It's way cheaper than any other wiring for that distance.

 

[kwired]

Is overhead an option?

excavating cost the same whether installing 6 AWG or 500KCMIL.

Overhead gets heavier the larger the conductors, may need more/better poles or additional guy wires, etc. depending on circumstances.

Just some things to consider.

If they are placing the RV receptacle that far away what else will they eventually want to power up in the vicinity?

Oversized or spare raceway at very least is maybe a good idea so you can increase conductor size or add a set in parallel?

 

[hillbilly1]

Yeah, I was thinking a 1-1-1-2 or even a 1-1-1-3, as there's 3 ac units on the RV

One that big probably has an EMS system the will not let all three start at the same time.

 

[karn]

Future options are always nice to consider, also I believe the RV thermostats usually have a time delay. Also I'm a little skeptical about derating the nuetral on a split load configuration, but at the same time I doubt theres a significantly unbalanced load between L1 and L2, or high harmonic content

 

[Frank DuVal]

Well, 600 feet is long! Southwire's calculator shows 50 amp load will need 2/0! I know, typical load is less than 50 amps.....

 

[Dennis Alwon]

It would help if you made sure of the total load. As Frank stated 600 feet is a long distance especially since you have to double it for the calculation.
Also 30 amp and 20 amp are usually 120v connection but the 50 amp unit I assume is 240v

 

[hillbilly1]

It would help if you made sure of the total load. As Frank stated 600 feet is a long distance especially since you have to double it for the calculation.
Also 30 amp and 20 amp are usually 120v connection but the 50 amp unit I assume is 240v

The 50 amp units are usually 120 volt loads only, they just split it between the legs. The EMS can “see” when a 30 amp dog bone is used, and limit what runs at the same time. Some high end units use 240 volt clothes dryers, if so installed.

 

[electrofelon]

That product is often found as a triplex with no EGC.

Mobile hole feeder is very common and has 4 conductors plexed.

 

[ramsy]

Mobile hole feeder is very common and has 4 conductors plexed.

Eventually found 1/0 with #2 EGC for $5,000 per 1kft vs $2300 without EGC.