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Going to start by describing the mess that I found.

Symptom: 220VAC Hot water heater not heating.

Cause Discovered: 1 phase missing in main panel. Upon investigation I discovered that the main feeder to this trailer was a temporary 50 AMP plug style connector. Someone had installed a 100 amp panel and main breaker inside the home. The plug had been been exposed to over-current and one of the prongs as well as half of the receptacle was completely destroyed.

Action Taken: Turned off the main breaker at the pole. 100 amp breaker feeding 1/0 (maybe 2/0) Aluminum conductors in Schedule 40 PVC conduit to the 220 VAC Receptical box.

Weather was getting cold and owner needed to move in within days. Due to limited time we had to rebuild ASAP.

Repairs Made.

Replaced 100 AMP main breaker inside Mobile home with 50 amp Breaker suitable for the temporary cable that was stamped 50 amps. It has a rubberized outside with molded plug and inside has 4 color coded conductors. It says it is rated for 50 amps and mobile home and RV use etc.

The plug and receptical were destroyed and the box was in bad shape. I could get new receptical but could not get a new cable with molded plug on short notice. I could get a new all weather box with a 40 amp 3 phase GFCI Breaker. I decided to go that way. Originally the temporary 50 amp cable came out of the plug (about 1 foot away from the trailer). Went under the ground (No conduit) for 2 feet under the skirt then up above ground and runs about 6 feet under the trailer. Then up inside the trailer to the main panel inside. Due to time constraints we removed the old box and receptical. Also cut off the molded plug that was destroyed. Conductors and insulation was in good shape so I installed it into the new all weather box with the GFCI (50 Amps). I left it going to the trailer the same way. Direct buried for 1-2 feet until it gets under the skirt. Then above ground and up into the main panel with the new 50 amp main I put in. I tested it at full load and also tested the GFCI. it works excellent even with the branches off. My only concern is that I did not have time to bury a conduit for the 50 amp "temporary" cable. Does it have to have one? The way I read the NEC (08) is yes it does if it is permanent. Also...I read I have to bury it all the way to where it comes up to go into the main panel inside the trailer. Is that correct? I think it is a sprig project either way. Just want to know if I can get away with leaving it the way it is due to being only 50 Amps and already in a cable as opposed to individual conductors.

Thank You

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What type of cord are you using? I have never seen a type of cord that it is rated for direct burial.

Article 550.10 is pretty clear regarding mobile home power cords but it is at the beginning of the Code that states you need to follow all listing, labeling, and manufacturer's instructions.

110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

According to the Code, you only need conduit where the cord is exposed to damage, passes through walls or floors, (or where buried because it is not listed / labeled for direct burial).

550.10(G) Protected. Where the cord passes through walls or floors, it shall be protected by means of conduits and bushings or equivalent.

I would just pass the cord through the skirt and not worry about burying it, or install some PVC from directly under the panel inside to the power pedestal and pull the cord into that. You could use a bushing to pass up into the mobile home. It should already have the bushing if it was wired right from the factory.

Good luck in the spring!

  • It's like this. It's stamped on the outside it is rated for a max of 50 amps and is interned for mobile home and recreation vehicle use. Old trailers from the 50's use to have this kind of hook up with the molded plus I'm told. google.com/… – Jarrod Dec 8 '15 at 13:33
  • You don't have to use a molded plug. You can buy a cord cap in the configuration you need and attach it to your cord after you pull it through the raceway. As long as the cord and plug are both rated for 50 amps. This is the configuration the Code shows in Article 510 homedepot.com/p/GE-50-Amp-Temporary-RV-Power-Outlet-U054P/… – ArchonOSX Dec 8 '15 at 18:29
  • Am I allowed to also have it hardwired into a 3 phase GFCI inside all weather enclosure? All properly rated for 50 A of course. Seems to be kind of a grey area when hard wiring RV/Mobile home under 50 amps. – Jarrod Dec 9 '15 at 14:26
  • It is 3 pole 4 wire but it is single phase 250 volt. And the MINIMUM is 50 amps. Article 550.10(I) says "Where the calculated load exceeds 50 amperes or where a permanent feeder is used..." (notice the OR). Then you can use a continuous raceway with THHN/THWN wire. Also, I don't see any requirement for GFCI on the feeder for the trailer. – ArchonOSX Dec 10 '15 at 2:49
  • The GFCI is just what I was able to get on Sunday. I do kind of like it. I don't know any information about the cord/cable because I can't the manufacturer's name. I can't say what kind of insulation they have but it does seem very hard plastic. Also....To me a "raceway" means a metal or plastic raceway that you run individual wires through that are not part of a cable. I was trained not to put a cable into a raceway due to heat issues. I used to be better at looking things up in my NEC but I haven't really used it since 08. Is there a section that defines raceway? – Jarrod Dec 11 '15 at 13:37

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