Electrical Question

[tonyp]

What is the maximum distance allowed between electrical inlet and breaker box? Apparently on sailboats it is 3 meters, are RV regulations the same? Thanks

[Inland RV Center, In]

Originally Posted by tonyp

What is the maximum distance allowed between electrical inlet and breaker box? Apparently on sailboats it is 3 meters, are RV regulations the same? Thanks

No, they are different.

Andy

[wahoonc]

Originally Posted by tonyp

What is the maximum distance allowed between electrical inlet and breaker box? Apparently on sailboats it is 3 meters, are RV regulations the same? Thanks

On my Airstream they are about 12" apart. You will need to find a copy of the RVIA standards (I believe that is the correct one). Also there most likely will have been a change in standards between 1959 and today.

Aaron

[AWCHIEF]

I don't think my "64 was built to any kind of electrical standards.

[tonyp]

I could not find a direct answer in the RIVA regs. Andy, you said they are different, do have have a more definitive answer? Mine (10 AWG) runs up the wall directly across the ceiling and half way down the opposite wall, its about 18-20'.
Tony

[Inland RV Center, In]

Originally Posted by tonyp

I could not find a direct answer in the RIVA regs. Andy, you said they are different, do have have a more definitive answer? Mine (10 AWG) runs up the wall directly across the ceiling and half way down the opposite wall, its about 18-20'.
Tony

RV's were "what's that thing" 63 years ago.

Standards basically did not exist.

Today is a very different story, thanks to technology and attorneys.

I would suggest you call Airstream at 937-5966111.

Andy

[Ag&Au]

I don't believe you will find a hard fast regulation. RV shore power is not like a dwelling, in that the source of power is already protected by circuit beakers rated for the maximum current. As far as AC power is concerned, a RV is more like an appliance than it is a dwelling. Therefor the only consideration needs to be ensuring the conductor size must be sufficient to carry (in most cases) 30 amps for the distance you chose. There are readily available tables to determine the conductor size.
Here is an example.

http://www.djsociety.org/Wire.htm


The proceeding is my opinion, not a statement of fact or regulation.

Ken

[TouringDan]

Ken

I completely agree with your assessment.

I don't believe there is distance requirement on a dwelling either, as long as there is a circuit breaker protecting the wire from the meter to the inside panel box.

Dan

[blkmagikca]

Originally Posted by tonyp

What is the maximum distance allowed between electrical inlet and breaker box? Apparently on sailboats it is 3 meters, are RV regulations the same? Thanks

Given that the electrical inlet is the end of the shore power cable, and given that most shore power cables are 25-feet in length, when you add the run through the wall to the breaker box, in my unit it comes to about 30 feet.

I had previously had a LY motorhome. One of my buddies undertook the project to convert the shore power from 30-amp to 50-amp. As part of due diligence, he called CSA to check on the requirements, and there was no mention of the maximum length of cable - so he installed a 100-foot shore power cable, and I never needed an extension cord.

[richinny]

now a 100' 50A cord HAS to cut into the payload a bit!

[tonyp]

Thanks for all the great replies.

[blkmagikca]

Originally Posted by richinny

now a 100' 50A cord HAS to cut into the payload a bit!

Nope, it didn't. Remember that it was #10 wire. Once the mod was done, I never had any issue with shore power. I also didn't get caught with insufficient wire to reach some of the pedestals installed in Ontario provincial parks, where they have driveways with a number of pull-thru sites with trees and bushes between the sites and the pedestals are set up between 2 sites and require a minimum of 50 feet of cable.

[lewster]

Interesting:

Every motor home or trailer that I work on with 50 amp shore service uses 6AWG from the plug that connects to the pedestal to the breaker box, or thru the transfer switch and then to the breaker box. Same with the big generators. IIRC, that is the current (no pun intended! ) RVIA specification.

[blkmagikca]

Lew, the actual amount of current is only 30-amps. As you know, the 50 amp service is really 220-volts, one half at 30 amps and the other at 20 amps (as per the breakers). Thus, there is no more than 30 amps going through the red or black sides of the wire. The RVIA code in this respect is much more stringent than the normal electrical code.

Thus the same size wire gauge as is used for 30-amp 110-v service can be used for 30-amp 220-volt service. Before the wiring was changed in my motorhome, my friend, who builds and services commercial kitchen equipment for hotels and restaurants, called CSA to confirm that his plans met their specifications.

The original schematics showed that the ATS switches also switched the neutral (white) wires. CSA told him that it was overkill and was not required. Thus the revised circuit to upgrade the shore power from 110-volts 30 amps to 220-volts 30-amps (known in the RV world as 50-amps) was able to also use the existing ATS switches, but rewiring them to function for 220-volts. In the course of the 6 years I had that motorhome, the only thing components that did not crap out on me was the shore power circuit.

I found that motorhome repairs were insanely expensive (mine was a '94 LY diesel pusher), and the breakdowns and repairs during the 6 years I had it (and serviced it regularly with Cummins) were:

- harmonic balancer came apart, taking the fan, fan housing, serpentine belt with it;
- the ECM (electronic control module AKA the computer) for the Allison tranny failed;
- two alternator failures,
- twice having the Bosch fuel injector pump rebuilt (each time was $3,500)
- chassis air conditioning system crapped out - even the dash control failed
- Rear engine seals leaked and needed to be changed

No repair was ever straightforward. Parts were available, but never stocked, so any repair meant I lost the use of the motorhome for weeks - try sitting in a field outside a garage in Fort Stockton TX for a week waiting for parts to come in to repair the harmonic balancer and its collateral damage. Last year I sold the motorhome and bought what I now have - a 32-ft Excella and a Dodge 3/4 ton truck. Best combo I've ever had - reliable, comfortable and easily serviced.

[Olroy]

Originally Posted by Inland RV Center, In

No, they are different.

Andy

Andy or anyone else who has ran a 50 amp cable into an old airstream. How do you get it thru the back bumper into the compartment where the panel box is 76 ambassador, hole is too small for 50Amp cable. I'm an electrician , I can wire it if I can get the feed into the compartment from outside without screwing up my airstream. roywest1114@msn.com for answer I think.. Roy West in Hills of KY

[markdoane]

Originally Posted by tonyp

What is the maximum distance allowed between electrical inlet and breaker box? Apparently on sailboats it is 3 meters, are RV regulations the same? Thanks

Correct answer is 450mm (18 inches). NEC 551.30.

[daveswenson]

Originally Posted by markdoane

Correct answer is 450mm (18 inches). NEC 551.30.

551.30 refers to generator installations, and the 18 inch limit does not have to be to the breaker board. Ie a junction box with a blank cover would satisfy the requirement.

[richinny]

Originally Posted by markdoane

Correct answer is 450mm (18 inches). NEC 551.30.

mark with all due respect.... my '94 34CL and the '11 34CL do not seem to meet those specs.

[richinny]

Originally Posted by daveswenson

551.30 refers to generator installations, and the 18 inch limit does not have to be to the breaker board. Ie a junction box with a blank cover would satisfy the requirement.

nor does that one.

i'll guess it to be 5' in my trailer.

[Protagonist]

Originally Posted by markdoane

Correct answer is 450mm (18 inches). NEC 551.30.

It's a little more than double that on my Interstate. I believe the 18-inch requirement is for the distance from an installed generator to the panel board, not for a shore power connection. My genset's outlet is less than 18 inches from the panel board, but my shore power inlet is farther.