using multiple feeder tap rules

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What are some opinions on if I can use two of the feeder tap rules on the same feeder. For example, can I use the unlimited outside tap rule and then use, say, the 10 foot tap rule for the portion inside? I am hung up on the "....shall not supply another conductor" phrase.
 

don_resqcapt19

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Location
Illinois
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retired electrician
Some inspectors may permit 10' of conductor inside to be considered "nearest the point of entrance". If so, then you are good to go with the outside unlimited length tap rule. If that is not nearest the point of entrance, you will have to provide an OCPD that is in a location that is acceptable to the AHJ.
 

GoldDigger

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Staff member
Location
Placerville, CA, USA
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Retired PV System Designer
Some inspectors may permit 10' of conductor inside to be considered "nearest the point of entrance". If so, then you are good to go with the outside unlimited length tap rule. If that is not nearest the point of entrance, you will have to provide an OCPD that is in a location that is acceptable to the AHJ.
I thought that the "nearest the point of entrance" was specific to service conductors, while the OP refers to a feeder.
Does the same limitation/permission appear for building feeders?
 
I thought that the "nearest the point of entrance" was specific to service conductors, while the OP refers to a feeder.
Does the same limitation/permission appear for building feeders?

The main body of 240.21(B)(5) states, ".....outside of a building or structure, except at the point of load termination...."

But then further down in (B)(5)(4)(b) it states, "inside, nearest the point of entrance...."

One thing I had not considered was the implication of needing a disconnect at/for the structure,which seems to be a deal breaker even assuming tap rules allow the original proposal. Clearly they thought to cover that in 240.21(B)(5) as opposed to making us default to 225.32
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I thought that the "nearest the point of entrance" was specific to service conductors, while the OP refers to a feeder.
Does the same limitation/permission appear for building feeders?
It is specific for feeders using the outside tap rule in 240.21(B)(5) and specific for all feeders to a "second building" in 225.32.
 

kwired

Electron manager
Location
NE Nebraska
The main body of 240.21(B)(5) states, ".....outside of a building or structure, except at the point of load termination...."

But then further down in (B)(5)(4)(b) it states, "inside, nearest the point of entrance...."

One thing I had not considered was the implication of needing a disconnect at/for the structure,which seems to be a deal breaker even assuming tap rules allow the original proposal. Clearly they thought to cover that in 240.21(B)(5) as opposed to making us default to 225.32

A separate structure can (generally) only be supplied by one feeder. That one feeder can still serve up to six disconnecting means, and a feeder tap would be allowed between the feeder and each disconnecting means.

You still can't tap a tap though. If you run outdoor feeder tap (of unlimited length) to the separate structure it must end in an individual overcurrent device.
 

MasterTheNEC

CEO and President of Electrical Code Academy, Inc.
Location
McKinney, Texas
Occupation
CEO
Greetings,

While many are going very deep and attempting to create this "loophole", the reality is you applied the tap rules to the outside conductor already. When you wish you apply a different set of tap rules you are indeed tapping a tap in my opinion and would be a problem. Clearly your AHJ might agree or disagree but that's the beauty of 90.4.

Choosing the Outside Tap rule and doing what you are asking to do makes it very hard to comply with 240.21(B)(5) in my opinion :

(5) Outside Taps of Unlimited Length. Where the conductors
are located outside of a building or structure, except at the
point of load termination, and comply with all of the following
conditions:
(1) The tap conductors are protected from physical damage
in an approved manner.
(2) The tap conductors terminate at a single circuit breaker
or a single set of fuses that limits the load to the ampacity
of the tap conductors. This single overcurrent device shall
be permitted to supply any number of additional overcurrent
devices on its load side.
(3) The overcurrent device for the tap conductors is an integral
part of a disconnecting means or shall be located
immediately adjacent thereto.
(4) The disconnecting means for the tap conductors is installed
at a readily accessible location complying with one of
the following:
a. Outside of a building or structure
b. Inside, nearest the point of entrance of the tap
conductors
c. Where installed in accordance with 230.6, nearest the
point of entrance of the tap conductors
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Greetings,

While many are going very deep and attempting to create this "loophole", the reality is you applied the tap rules to the outside conductor already. When you wish you apply a different set of tap rules you are indeed tapping a tap in my opinion and would be a problem. Clearly your AHJ might agree or disagree but that's the beauty of 90.4.

Choosing the Outside Tap rule and doing what you are asking to do makes it very hard to comply with 240.21(B)(5) in my opinion :

(5) Outside Taps of Unlimited Length. Where the conductors
are located outside of a building or structure, except at the
point of load termination
, and comply with all of the following
conditions:...
(4) The disconnecting means for the tap conductors is installed
at a readily accessible location complying with one of
the following:
a. Outside of a building or structure
b. Inside, nearest the point of entrance of the tap
conductors
c. Where installed in accordance with 230.6, nearest the
point of entrance of the tap conductors
It seems pretty clear to me.
You do not get to separately apply the 10 foot tap rule for the inside part of the continuous conductor.
But if there is no outside disconnecting means or splice the only remaining question is whether your AHJ will allow a ten foot length to the termination at a single OCPD " Inside, nearest the point of entrance". Or whether that is too far to qualify as "nearest".
 

iwire

Moderator
Staff member
Location
Massachusetts
But if there is no outside disconnecting means or splice the only remaining question is whether your AHJ will allow a ten foot length to the termination at a single OCPD " Inside, nearest the point of entrance". Or whether that is too far to qualify as "nearest".

I would ask the AHJ if I can apply the rules found in 230.6
 

Smart $

Esteemed Member
Location
Ohio
I would ask the AHJ if I can apply the rules found in 230.6
The tap requirements say you can, under 240.21(B)(5)(4)...
c. Where installed in accordance with 230.6, nearest the point of entrance of the tap conductors

Also in...
225.32 Location. The disconnecting means shall be installed
either inside or outside of the building or structure
served or where the conductors pass through the building or
structure. The disconnecting means shall be at a readily
accessible location nearest the point of entrance of the conductors.
For the purposes of this section, the requirements
in 230.6 shall be utilized.
 

MasterTheNEC

CEO and President of Electrical Code Academy, Inc.
Location
McKinney, Texas
Occupation
CEO
But the provision for the outside rule demands it...does it not?

Comments based on the 2017 National Electrical Code.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
But the provision for the outside rule demands it...does it not?

Comments based on the 2017 National Electrical Code.

The provision of the outside tap rule are identical to the other places in the code that require termination "nearest the point of entrance". In some areas the AHJ will permit 10 to 15' inside to comply with those rules. In other places, they read "nearest" as exactly that...you come into the building and you terminate the conductors. T

The only issue here is what the OP's AHJ considers "nearest the point of entrance", as it is clear that you can't use more than one tap rule without hitting an OCPD between them
 
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