120/208 cord on a 120/240v service

sunny1

sunny1

Member
Location
Washington State
Occupation
electrician
I need to provide a 30 amp receptacle for a trailer that has a 120/240 single phase service. The trailer arrived with a three phase 120/208v five wire receptacle. The owner of the trailer reconfigured the panel in the trailer to accomodate the single phase service, but I am still asking them to change the cord end to a four wire 120/240, as I didn't like the idea of the 208v rated cord being fed by a 240v circuit. In looking into it, I noticed all the standard three phase 5 wire configurations cord/receptacles are 120/208, which makes me wonder if I am being overly cautious. What would one do if they needed to connect a three phase piece of equipment if the service is 120/240 three phase delta? Thanks in advance .
 
That's kind of confusing, but I'll give it a go--
(The trailer has a five wire receptacle or a plug? Also, that's a confusing use of the word "service".)

The plugs/receptacles will be voltage rated for 250 volts and the cord for 300 or 600 depending on type, so that's not a problem. That's different from the voltage you'd expect to find on it.

Properly, for 120/240 1-ph you'd provide a L14-30 (or non-locking 14-30) and change out the trailer's cord end to match.

As for a 120/240 delta feed, if the neutral isn't needed a L15-30 or 15-30 straight blade (good luck finding one) would do the job. If the neutral is needed, I think you're out of luck with NEMA parts.
 
Thank you for giving it a go despite my terribly worded post! the trailer arrived with a NEMA L21-30P cord end, (not a receptacle), which is rated 120/208volt. I need to provide a receptacle for this from a single phase 120/240 service, so I want him to change the cord end on the trailer since it is only rated for 120/208v. Am I correct in my concern?

The only reason he didn't want to change the cord end on the trailer is because he is hoping to use the cord he needs to build to reach the receptacle I will provide for something else in the future. Obviously I'd like to provide him with what he wants as long as it is safe.

thanks again
 
I would change the plug on the cord to a 14-50 to match a 240/120 RV receptacle and give him the existing plug for future use,
(He can modify his panel form single phase.)
 
augie47 said:
I would change the plug on the cord to a 14-50 to match a 240/120 RV receptacle and give him the existing plug for future use,
(He can modify his panel form single phase.)
Click to expand...
My error.. I'm used to 50 amp RV..., If he needs 30 amp 120/240 I would change the plug & receptacle accordingly
 
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