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#170025 - 10/24/07 01:26 PM RV Pedestals Feed though rateings  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 822
Michigan
RV part not a Trailer park. Several Pedestals on a 4/0 Alum. Line. Breakers 200 amp. Pedestals are rated 125 amp. Lugs to pass though are termintated on the 125 amp buss. Each Pass through lug in a single unit(in & out one solid bar two term points) Since Terms never really pass through the bar JUST feed the bar(like a tap) Is the 125 amp rateing on the Pedestal OK. This is done on trailer parks all over the counrty. Other opinons Please


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#170060 - 10/25/07 10:33 AM Re: RV Pedestals Feed though rateings [Re: Yoopersup]  
sabrown  Offline
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Joined: Dec 2002
Posts: 302
Ogden, Utah, USA
Interesting, as I have called out many of these and just worry about the wire sizes that can feed through (upwards of 250MCM main wire size on the brand I like), yet as I have known the mains are rated for only 125 amp.

I may be wrong, but I have kept to the following:

1- I have been using the 75 degree column only for any wire ampacity installed. This is probably not due to rating of the feed thru lugs which are likely rated for 90 degree, but due to the rating of the mains (the wire that feeds the disconnects) and is according to Mfg. literature.

2- I have assummed, maybe incorrectly, that the 125 amp mains is protected by the overcurrent devices in the pedestal and the feeder rules.

3- When I am over 250 (255 amp on the 75 degree of 250 MCM) amps on a feeder or using larger wire than 250 MCM, I tap out of handholes (grade level pull boxes).

It is possible that I have been having these installed incorrectly and there are overheating issues that I can not conceive. If so, the terminals are just oversized to accept large conductors due to voltage drop and we need to tap out of a pull box until the connected load (due to outside tap rules) is below 125 amp. This does not sound logical.

Our best source of correct information will be UL or other testing lab. If you are concerned enough, ask and let us all know, especially if I am wrong.

Shane


#170090 - 10/26/07 07:33 AM Re: RV Pedestals Feed though rateings [Re: sabrown]  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 822
Michigan
Most RV Pedestals Do Not Have Mains , 125 amp buss breakers for each outlet after that , could be a 50-30-20-or a 30-20
or a 20. Thats the way there build and go in.


#170092 - 10/26/07 09:10 AM Re: RV Pedestals Feed though rateings [Re: Yoopersup]  
sabrown  Offline
Member
Joined: Dec 2002
Posts: 302
Ogden, Utah, USA
Correct, the mains that they refer to in my opinion is the wire from the terminal to the breakers.



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