# Feeder Tap rule question



## telsa (May 22, 2015)

Your #6 taps have to terminate in an OCPD. ( fuse or C/B )

Without knowing the temperature rating of said OCPD... I hesitate.

You may be looking at 60 degree rated terminations. ( ie 55 Amps )

Since the feeder is protected by a 100 A C/B your specifications sound conservative, as even 55A > than 1/3 x 100 A.

&&&&

Are you really dealing with an over sized feeder due to voltage drop considerations -- which can't easily terminate in a 60 A lug set ? ( or back wired C/B ? )

If that's the nature of your tap, it would appear that you're good to go.

Remember that the 25 feet are measured down the conductors -- not across the floor.


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## Jason8161 (Feb 17, 2016)

#6 taps will be feeding line side of r.v. panel boards


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## Jason8161 (Feb 17, 2016)

30 and 20 amp breakers to outlets


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## telsa (May 22, 2015)

Jason8161 said:


> #6 taps will be feeding line side of r.v. panel boards


You mean recreational vehicle_ pedestals_ ?

You can tap and tap -- as long as each and every tap terminates in an OCPD.

I've seen pedestals that had OCPD (typical) -- and some that didn't -- must have been grandfathered or hack work.

http://www.bing.com/images/search?q...vehicle+electric+pedestal+for+power&FORM=IGRE


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## Jason8161 (Feb 17, 2016)

So answer me this if you may...and I sure you may. I have these rv pedestals fed off a 100 amp breaker at service panel. 4/0 alum wire for voltage drop calculations. 100 amp breaker max wire size is 1/0....I see a bunch of threads where it says you can splice in panel....but splicing 1/0 from breaker to a 4/0 to the rv panels doesn't that put you back in voltage drop issues?


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## telsa (May 22, 2015)

Jason8161 said:


> So answer me this if you may...and I sure you may. I have these rv pedestals fed off a 100 amp breaker at service panel. 4/0 alum wire for voltage drop calculations. 100 amp breaker max wire size is 1/0....I see a bunch of threads where it says you can splice in panel....but splicing 1/0 from breaker to a 4/0 to the rv panels doesn't that put you back in voltage drop issues?


Voltage drop can only be calculated when loads, distances and conductors are known.

Without a wiring diagram -- I'm at sea.

Since a 100 A breaker is engineered to pass 80 Amp (continuous) and your loads are most _unlikely_ to be continuous... it would appear that your hefty conductors are plenty to prevent voltage sag.

But then, RV parks often entail substantial distances.

The last one I frequented ran 4160 V 3-phase to dry type transformers all over the place. 

( Fused disco, NEMA3R mounted to the transformer exterior... all conductors buried.)

Then these units were tapped to a cluster of RV pedestals, each with OCPD.

4160V to 208Y120 dry type transformers are cheap and easy to wire -- so it's a popular solution. You'd have to have medium voltage at the Service, of course.

Your best bet is to just scope out the most distant run, assume a hot day, and a full park. Then run load calcs on it -- then figure the voltage drops.

All nearer runs will be in better shape than the longest run, so it's your only worry.


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