Article 551

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mj63

Member
Hi, long time lurker first time poster here.

I was sent out to re-feed some rv park pedestals that have a 50 amp 240, 30 amp 120, and a 20 amp 120 receptacles in them.
I am a bit confused at how these guys ran the feeds to these.
They ran 350 KCMIL from a 200 amp fused bucket to the pedestal post which is feed thru and rated 200 amps, but then they are hooked to the heads with the receptacles and that is only rated at 100 amps, I am confused about this, is this normal wiring for RV parks?
 

mcclary's electrical

Senior Member
Location
VA
Hi, long time lurker first time poster here.

I was sent out to re-feed some rv park pedestals that have a 50 amp 240, 30 amp 120, and a 20 amp 120 receptacles in them.
I am a bit confused at how these guys ran the feeds to these.
They ran 350 KCMIL from a 200 amp fused bucket to the pedestal post which is feed thru and rated 200 amps, but then they are hooked to the heads with the receptacles and that is only rated at 100 amps, I am confused about this, is this normal wiring for RV parks?



What couples the 100 amp receptacles to the 200 amp feed thru's? Do rec. feeders land on the bottom lugs? If so, the set up is illegal.
 

mj63

Member
Thanks for the responses,

On the feed thru lugs mounted in the pedestal post there is a smaller lug mounted on the same stud as the larger lugs.

There is a #2 copper that runs from the smaller lugs up to the pedestal head, It then feeds a main bus that has individual breakers on it for each receptacle.

Does the fact that the receptacles have their own breakers make it ok to have 100 amp rated equipment on 200 amp fuses? It seems that if there was a problem with the pedestal head (maybe the plastic insulator that seperates the bussing from the can melts)the equipment could be damaged due to the 200 amp fuses feeding the 100 amp gear, or have I confused myself
 

mcclary's electrical

Senior Member
Location
VA
Thanks for the responses,

On the feed thru lugs mounted in the pedestal post there is a smaller lug mounted on the same stud as the larger lugs.

There is a #2 copper that runs from the smaller lugs up to the pedestal head, It then feeds a main bus that has individual breakers on it for each receptacle.

Does the fact that the receptacles have their own breakers make it ok to have 100 amp rated equipment on 200 amp fuses? It seems that if there was a problem with the pedestal head (maybe the plastic insulator that seperates the bussing from the can melts)the equipment could be damaged due to the 200 amp fuses feeding the 100 amp gear, or have I confused myself



That setup sounds legal, but I'm still not quite picturing what you have. But if there is a breaker protecting the conductors that feed the 100 amp receptacle, then you're fine.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
MJ, welcome to the forum! :)

It sounds like you have #2 taps on 350 feeders, and the taps feed ML buses with BC breakers. You're questioning whether the unfused #2 tap is compliant, right?

Check out 240.21(B).
 

mj63

Member
Larry,
I apologize for the delay in responding, yes that is basically my concern and the fact the assembly "the pedestal head" that has the receptacles and is only rated at 100 amps.
For comparison it seems that it would be the same as running a 100 amp branch circuit to feed a MLO 60 amp panel that has less than 6 breakers, is this considered a legal install?
 
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