Tap Clarification

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ASG

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Work in NYC
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Electrical Engineer, PE
I'm drawing a blank here. Can somebody explain how/why a full size feeder tap is not a tap (in regards to the tap rules)? I feel like I've heard this many times on here but I've never quite understood it.
 

petersonra

Senior Member
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Northern illinois
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engineer
I'm drawing a blank here. Can somebody explain how/why a full size feeder tap is not a tap (in regards to the tap rules)? I feel like I've heard this many times on here but I've never quite understood it.

A tap is a conductor not protected at its ampacity at the source. By definition it cannot be full size.
 

infinity

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Also you could have conductors smaller than those in the feeder spliced to the feeder and still not have a tap. Here's a set of parallel 300 kcmil spliced to a set of #3/0 and this is not a tap since the OCPD ahead of the 300's is 200 amps.

20130206_100136.jpg
 

GoldDigger

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Placerville, CA, USA
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Retired PV System Designer
One place this is likely to happen is where a long feeder is oversized for VD control but you go with the smaller conductor size for short distances at the termination(s) to make it easier to handle the wiring.

Tapatalk!
 

jaylectricity

Senior Member
Location
Massachusetts
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licensed journeyman electrician
I'm drawing a blank here. Can somebody explain how/why a full size feeder tap is not a tap (in regards to the tap rules)? I feel like I've heard this many times on here but I've never quite understood it.

Why would you want to limit yourself to tap rules by calling your full size feeder a tap?
 

ASG

Senior Member
Location
Work in NYC
Occupation
Electrical Engineer, PE
It was the definition in 240.2 I was missing. I was looking for a definition in 110, didn't see it there and just then couldn't connect the dots of how it wasn't a tap that had to meet the tap rules.
 

kwired

Electron manager
Location
NE Nebraska
It was the definition in 240.2 I was missing. I was looking for a definition in 110, didn't see it there and just then couldn't connect the dots of how it wasn't a tap that had to meet the tap rules.
And keep in mind that that definition is in 240 and not art 100 so that means the definition only applies when the term is used in art 240. If the word "tap" appears in other articles it is not using that definition. Some of the examples we have been given with "taps" are not art 240 applications - in particular the content covered by 240.21.

Add: maybe I should have worded that differently at the end there. Some of the examples here are not examples where the allowances of 240.21 are being taken advantage of, but one may call them taps outside the context of art 240.
 
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