Parallel Feeders

[ThorHs]

What is the purpose of Parallel Feeders and when and where shoud I use them

 

[charlie b]

The purpose is to allow you to use two smaller conductors, instead of one larger conductor, while still achieving the minimum ampacity for the circuit. As to when to use them, it depends on many factors. Cost is probably the biggest factor, but you have to include the cost of labor in that equation. A single larger conductor might be cheaper to buy, but it might also be far more expensive to install.

Are you looking for something in particular, or is this just a general question?

 

[iwire]

What is the purpose of Parallel Feeders and when and where shoud I use them

Charlie gave you some good info I will just try to add some to it.

You can not run parallels less than 1/0 in size (generally)

Think large feeders or services.

Once you get above 400 amps running parallel conductors starts to make good sense.

We typically use copper so my experience may be different from those used to Aluminum

A set of 600 Kcmil copper will provide 420 amps of capacity and is about as large a conductor as I want to have to handle, pull, terminate pay for (about $10 per foot) etc.

So for a 1600 amp service or feeder we would likely run four sets of 600s.

A 4000 amp service ten sets of 600s etc.

 

[pault587]

In the example above do the feeders go in a conduit per phase or does each conduit have to contain all 3 phases?

 

[steve66]

In general, you have to have all three phase conductors in each conduit (if there is a neutral and/or ground, they are also ran in each conduit).

However, I think there is an exception that lets you bundle each phase in a separate conduit for underground installations with non-metallic conduit.

I might also add that parallel conductors need to be the same size, type, and length. They are also ran in the same size and type of conduits. This all keeps the ampacity equal on each parallel run.

Steve

 

[pault587]

Thank you
-Paul

 

[hardworkingstiff]

A set of 600 Kcmil copper will provide 420 amps of capacity and is about as large a conductor as I want to have to handle, pull, terminate .....

Put me down for 500 as being the largest I would like to handle and I prefer to keep them 350 or smaller.

 

[iwire]

That's correct if memory serves. Not sure about the non metallic though, as long as the conduits are very close together,

Steve was correct, isolated phase arrangements must only be done in non-metallic conduit.

 

[hockeyoligist2]

temp without conduit

temp without conduit

In general, you have to have all three phase conductors in each conduit (if there is a neutral and/or ground, they are also ran in each conduit).

However, I think there is an exception that lets you bundle each phase in a separate conduit for underground installations with non-metallic conduit.

I might also add that parallel conductors need to be the same size, type, and length. They are also ran in the same size and type of conduits. This all keeps the ampacity equal on each parallel run.

Steve

We have an emergency generator that is used all over the place. The boss bought 500's and we parallel them where they are needed. they are temp always, so not in conduit. What happens in that situation? They are laying on the ground kinda bunched together with caution tape around them.