Pigtail

[blues]

I have a 80 ampere circuit that will run about 2800 feet to a load. Obviously the cable will have to be upsize for voltage drop. I believe I am allowed to pigtail the branch circuit but I am unsure as to how this might be accomplished given the large wire size required. Is there an adapter kit available to make the transition? Any suggestion would be greatly appreciated.

Thanks,
Dan Craven

 

[iceworm]

I like the polaris connectors. Or a power distribution block. Or split bolts maybe. Depends on the wire sizes.

ive

 

[petersonra]

I have a 80 ampere circuit that will run about 2800 feet to a load. Obviously the cable will have to be upsize for voltage drop. I believe I am allowed to pigtail the branch circuit but I am unsure as to how this might be accomplished given the large wire size required. Is there an adapter kit available to make the transition? Any suggestion would be greatly appreciated.

Thanks,
Dan Craven

2800 feet @ 80Amps is a big chunk of wire.

have you considered alternatives?

 

[John120/240]

Would it be practical to use two transformers, step up then step down. Or can the POCO set a new service at the desired location ?

 

[iceworm]

Would it be practical to use two transformers, step up then step down. Or can the POCO set a new service at the desired location ?

Always - just an economics problem.

ice

 

[masterinbama]

At 480 single phase it's calling for 1000 MCM conductors.

 

[petersonra]

At 480 single phase it's calling for 1000 MCM conductors.

Two 1000KCM and a ground is probably close to $100,000 worth of wire.

I bet your electrical supply house will bring you donuts for a month for that kind of order.

 

[blues]

Pigtail

Two 1000KCM and a ground is probably close to $100,000 worth of wire.

I bet your electrical supply house will bring you donuts for a month for that kind of order.

It is 3phase and I figured 700kcmil. If I use a power distribution block my smaller conductor to the breaker must have a maximum length of ?

 

[GoldDigger]

It is 3phase and I figured 700kcmil. If I use a power distribution block my smaller conductor to the breaker must have a maximum length of ?

As long as the increase in wire size is only for voltage drop purposes, there is no Code limit to the length of the smaller conductor.
Since the smaller conductor is still protected adequately by the breaker, it is not a tap.

 

[iceworm]

It is 3phase and I figured 700kcmil. If I use a power distribution block my smaller conductor to the breaker must have a maximum length of ?

As noted in previous posts: No, it is just a voltage drop problem. Calculate the Vd on the big wire, calculte the Vd on the smaller wire. Add together. Verify Vd is less than (or equal) to spec.

Just curious - is this a 4160V 3ph or 3ph, 480V 3ph, or 208V 3phase?

ice

 

[iceworm]

As long as the increase in wire size is only for voltage drop purposes, there is no Code limit to the length of the smaller conductor.
Since the smaller conductor is still protected adequately by the breaker, it is not a tap.

GD - educate me. Other than voltage drop, what other reasons are there for increasing conductor size?

Hummm ... Derate for number of conductors in conduit - doesn't seen likely here. Derate for ambient temp - could be but not likely here.

Other than these two, what other reasons ....?

ice

 

[GoldDigger]

GD - educate me. Other than voltage drop, what other reasons are there for increasing conductor size?

Hummm ... Derate for number of conductors in conduit - doesn't seen likely here. Derate for ambient temp - could be but not likely here.

Other than these two, what other reasons ....?

ice

OK. Too late to edit, but change "As long as...." to "Since....."
I cannot think of any other reasons either.

If reason for increased size is derate for temp or fill, then apply the 10 foot or 10% rule for circuit of mixed ampacity rating? Or would the "circuit" in question end at the point where the pigtail is attached? I think we have gone back and forth on that one at one time too.

 

[Smart $]

... Or would the "circuit" in question end at the point where the pigtail is attached? I think we have gone back and forth on that one at one time too.

No, it ends at terminations. Splices are not considered terminations.

 

[iceworm]

No, it ends at terminations. Splices are not considered terminations.

And a "power distribution block" is considered ... what?

ice

 

[Smart $]

And a "power distribution block" is considered ... what?

ice

The block itself is a connecting means for a splice, tap, or both. We are only concerned with the function. It would be a termination for tap conductors, but also for feeder conductors if that's where they end.

 

[xformer]

It is 3phase and I figured 700kcmil. If I use a power distribution block my smaller conductor to the breaker must have a maximum length of ?

Dont forget about 250.122(B)