Tap conductor

[hhsting]

I have 208/120V 400 amps fused service disco inside building incoming line side 4#500 kcmil service conductors. Load side of the service disco lug I have conductor A 4#3/0 + #3/0G to Panel A and at same point load side of service disco lug I have conductor B 4#3/0 + 3/0G to Panel B.

I would be assuming Conductor A is tap conductor so is conductor B but these are not feeder taps as their is no feeder being tap both are connected at single point load side lugs of service disco. So what tap conductor rules apply for conductors A and B in code?

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[texie]

I have 208/120V 400 amps fused service disco inside building incoming line side 4#500 kcmil service conductors. Load side of the service disco lug I have conductor A 4#3/0 + #3/0G to Panel A and at same point load side of service disco lug I have conductor B 4#3/0 + 3/0G to Panel B.

I would be assuming Conductor A is tap conductor so is conductor B but these are not feeder taps as their is no feeder being tap both are connected at single point load side lugs of service disco. So what tap conductor rules apply for conductors A and B in code?

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It is still a tap. It begins on the load side of the disco. Do you have the appropriate lugs on the disco for the conductors? Do the panels have a main breaker of the correct size?

 

[hhsting]

It is still a tap. It begins on the load side of the disco. Do you have the appropriate lugs on the disco for the conductors? Do the panels have a main breaker of the correct size?

Poster#1: This installation is not PV. Panels A and B are 200 amps MLO, Panel A 60 feet and Panel B 80 feet from main service disco in building. Its not fdr tap nor its outside fdr tap. So what kind of tap on code would apply?

 

[jaggedben]

The tap rules are in 240.21(B). The fact that the conductors are both directly connected to the disco doesn't change that they are still tap conductors according to the code.

You posted in the PV forum but didn't ask a PV specific question. Is there a concern about where you can interconnect an inverter output?

 

[jaggedben]

Poster#1: Panels A and B are 200 amps MLO, Panel A 60 feet and Panel B 80 feet from main service disco in building. Its not fdr tap nor its outside fdr tap. So what kind of tap on code would apply?

Sounds like a non-compliant installation because both panels are MLO. They need main breakers, especially if you want to connect a solar system anywhere in there.

 

[electrofelon]

Poster#1: This installation is not PV. Panels A and B are 200 amps MLO, Panel A 60 feet and Panel B 80 feet from main service disco in building. Its not fdr tap nor its outside fdr tap. So what kind of tap on code would apply?

It sounds non compliant. The length is too long, there is no OCPD at the load end of the taps, and the panelboard is not protected per 408.36. I believe its called an "I'll decide" tap

 

[texie]

Poster#1: This installation is not PV. Panels A and B are 200 amps MLO, Panel A 60 feet and Panel B 80 feet from main service disco in building. Its not fdr tap nor its outside fdr tap. So what kind of tap on code would apply?

I did not notice this was in the PV forum but I went on the assumption that this is a 400 amp fusible service disco and did not even think of PV.
Assuming this is correct, my answer does not change. Your additional detail that the panels are MLO and the distances involved indicate more code issues.

 

[hhsting]

It sounds non compliant. The length is too long, there is no OCPD at the load end of the taps, and the panelboard is not protected per 408.36. I believe its called an "I'll decide" tap

Ok. Aside from that, these are tap conductors 240.21(B) is feeder tap, 240.21(C) is transformer secondary tap, 240.21(D) is service conductors, 240.21(E) is busway taps, 240.21(F) motor circuits taps, 240.21(G) is conductors from generator terminals and 240.21(H) is battery conductors.

I cannot find in code length of tap conductors and how they are suppose to be protected in poster#1 and #3.

 

[electrofelon]

Ok. Aside from that, these are tap conductors 240.21(B) is feeder tap, 240.21(C) is transformer secondary tap, 240.21(D) is service conductors, 240.21(E) is busway taps, 240.21(F) motor circuits taps, 240.21(G) is conductors from generator terminals and 240.21(H) is battery conductors.

I cannot find in code length of tap conductors and how they are suppose to be protected in poster#1 and #3.

You have a feeder, it is a feeder tap.

 

[Adamjamma]

Ok, student probably going to ask dumb question here, but,
feeders are different from service entrance cables... if I recall,
so, if you are feeding a panel, or sub panel, and it has a main breaker of 200 amps, then you start with that value, and then figure your voltage drop for the distance and the rating factors for the installation method, with no discount like the service entrance cable would get.. so you could be using greater than 4/0 size, depending on distance and factors, rather than an entrance being allowed 2/0 in many cases...

or or am I totally confused and need to go back over that section again??

 

[hhsting]

You have a feeder, it is a feeder tap.

240.21(B) "Conductors shall be permitted to be tapped, without overcurrent protection at the tap, to a feeder as specified in....".

I have conductors tapped to load side of fused service disconnect terminals not feeders. How does 240.21(B) apply?

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[electrofelon]

240.21(B) "Conductors shall be permitted to be tapped, without overcurrent protection at the tap, to a feeder as specified in....".

I have conductors tapped to load side of fused service disconnect terminals not feeders. How does 240.21(B) apply?

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There was a proposal to add language stating that a feeder tap may start at the load terminals of a device, but it was rejected as being Un necessary. You dont actually need a wire type feeder to make a feeder tap.

 

[jaggedben]

240.21(B) "Conductors shall be permitted to be tapped, without overcurrent protection at the tap, to a feeder as specified in....".

I have conductors tapped to load side of fused service disconnect terminals not feeders. How does 240.21(B) apply?

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Look at the definition of a tap conductor. Both sets of conductors on the load side of your disconnect meet the definition.