question about taps

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Electron_Sam78

Senior Member
Location
Palm Bay, FL
I have a situation at work where there is a distribution panel with a circuit tapped from it - there is a terminal block mounted on the bus bars with the conductors coming from it (no breaker). The tapped circuit runs underground to another distribution panel but it terminates in lugs at the panel with no OCPD. This is a violation of the tap rule correct? It should be terminated at an OCPD sized to protect the tap conductors according to what I'm reading in the NEC.
 

KevinVost

Senior Member
Location
Las Vegas
It is a violation as you described it. If the tap is over 10' but less then 25' it must terminate at an OCD. The tap conductors must also be sized 1/3 of the ampacity of the breaker feeding the buss. If the tap is over 25' it needs an OCD at the panel it originates in. Aside from that I would think that the listing of the panel and or terminal block would not allow the block to be mounted directly to the buss.
 

Electron_Sam78

Senior Member
Location
Palm Bay, FL
The panels are housed in a shed built specifically to protect them from the weather. The tap is over 25' but it is outside of a building - underground. Do you have code references?
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
If the conductors are protected by the overcurrent device feeding the panel (they are the same size as), they are not considered as tap conductors.
 

KevinVost

Senior Member
Location
Las Vegas
Taps are at 240.21 B 2. If the wire is full sized (rated for the OCD on the panel) you may not have a tap (although I would still question a terminal block attached to the buss), however seperate structures require their own disconnecting means at the structure, 225.31, so if your feeder goes from one building to the next, you need a disconnect & OCD. If you do have outdoor taps check 240.21 B 5, it has requirements for outdoor taps of unlimited length, one of which is it must end in an OCD. Post some pics if you can, might help to get a clear idea of what you have.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
This may be a case of semantics.

There are many panels available with 'lugs' mounted to the busbars. They are commonly called thru-feed lugs if they are mounted at the end of the busbars opposite from the incoming line.
 

Electron_Sam78

Senior Member
Location
Palm Bay, FL
This may be a case of semantics.

There are many panels available with 'lugs' mounted to the busbars. They are commonly called thru-feed lugs if they are mounted at the end of the busbars opposite from the incoming line.


If a smaller rated wire were attached to the feed through lugs then it would still be a tap right?
 

Electron_Sam78

Senior Member
Location
Palm Bay, FL
pics of my situation

pics of my situation

I think the sheds were built to keep from having to use the more expensive outdoor equipment. As you can see I've inherited a mess. They have left the covers off and installed fans in the sheds because of overheating. Yes those are dead mice and a dead snake in the back of the secondary panel. It's gonna be a long summer...

BTW Please cite all violations you see. I'm making a list of things to get done. We've got Obama money to spend so I can trench new wire, replace panelboards, install large, expensive breakers, etc...
 

KevinVost

Senior Member
Location
Las Vegas
Yikes, what a mess. Now that you have looked at it, are the second panel feed wires taps or are they the same size as the feeder to the panel? The terminal block mounted to the buss I've see before, but its be a long time. I would say, as stated by others, if the second panel feed is full sized NO TAP. However the main panel has wiring not in a raceway, are you going to be fixing the whole thing? If so, I hope it's a good payout :D.
 

Electron_Sam78

Senior Member
Location
Palm Bay, FL
Yes it's definitely a tap. The tap conductors are about half the size of teh main feeders. I am going to try to fix everything this year. We'll see how that works out...
 
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