800A Transfer switch, wrong lugs

[Npstewart]

Hello everyone.

Working on a project with a 800A cummins transfer switch. The transfer switch was actually provided by the owner and given to the electrician to install. The problem is that our drawings indicated (2) sets of #600 kcmil but the owner ordered a the wrong lugs for it. The lugs can not accept the #600 wire because the lugs are only meant to accept (4) sets of #400 wire (max). Cummins claims they cannot send a new set of lugs because it would void the UL listing on the equipment.

The (2) sets of #600 wire is already pulled and into place and has been there well before the transfer switch was on site.

Question:
Would it be permissible to make a tap within the transfer switch and change the conductors to (4) sets of #3/0? The inside of the ATS is pretty large and there seems to be ample room in there.

 

[ron]

Seems like a reasonable solution. Convert each 600 into two 3/0.

 

[iwire]

I think Cummings is nuts.

 

[don_resqcapt19]

If they could have provided it as part of the original order, then they can provide it as a part after the original order was shipped without an adverse effect on the listing.

 

[Npstewart]

After speaking with the plans examiner (also a member of this forum), we ran into another issue. If the transfer switch is fed from a wireway, you would have to "tap" the "tap" conductors. However, if the (4) sets of conductors are rated for greater or the same as the the (2) sets of conductors, is this still a tap?

I drew a quick picture to illustrate the situation..

 

[Npstewart]

Looks like everyone is stumped.

 

[steve66]

After speaking with the plans examiner (also a member of this forum), we ran into another issue. If the transfer switch is fed from a wireway, you would have to "tap" the "tap" conductors. However, if the (4) sets of conductors are rated for greater or the same as the the (2) sets of conductors, is this still a tap?

I drew a quick picture to illustrate the situation..

No, its only a tap if the ampacity of the conductors are reduced.

What you have is a splice.

P.S. I don't think there is any way 3 sets of splices for 2 sets of 600 KCM to 2 400 kcm cables is going to fit in an ATS. Or at any rate, it will be a real mess.

I agree with Bob. Cummins is crazy - they should just provide the right lugs. What 800A ATS won't take 2 sets of 600 KCM?

 

[Npstewart]

No, its only a tap if the ampacity of the conductors are reduced.

What you have is a splice.

P.S. I don't think there is any way 3 sets of splices for 2 sets of 600 KCM to 2 400 kcm cables is going to fit in an ATS. Or at any rate, it will be a real mess.

I agree with Bob. Cummins is crazy - they should just provide the right lugs. What 800A ATS won't take 2 sets of 600 KCM?

The only reason why I could see that they may have a point is because there are all these small low voltage connections on the lugs. Each individual lug has a small low voltage connection probably for some type of control wiring . If the lugs were changed, im not sure how this would effect the operation of the switch? Probably send out some type of error message.

Also, this ATS is probably 7 feet tall and 3 feet wide. I really think there is plenty of room although I am asking the electrician to make sure he can actually physically get this done.

 

[Strathead]

Looks like everyone is stumped.

That is because what you have written is confusing. The PDF doesn't show any taps. Or maybe it does. You show 3 sets of 400 coming in to a gutter 2 sets of 600 coming out with no explanation. So the first question is, why not just bring the 3 400's out. Assuming there is a reason, I will address another part of your question if I understand it correctly. First, I would call Burndy and ask whether the part number AYPO600 offset reducer is capable of fitting in a lug listed for 400KCMIL. The plug diameter is .73 and the diameter of 400 is .728. That said, if you bring three 400 KCMIL in and 2 600KCMIL out of a 5 hole polaris lug, it is not a tap, it is a splice.

 

[Npstewart]

That is because what you have written is confusing. The PDF doesn't show any taps. Or maybe it does.

Wasn't my intention to make it confusing. I drew the diagram very quick because sometimes these forum posts have a tendency to take off before I can clarify what is actually happening. The taps are shown in a simplistic way. I am show two lines running into a vertical line with 4 lines coming out.

First, I would call Burndy and ask whether the part number AYPO600 offset reducer is capable of fitting in a lug listed for 400KCMIL

Working on this.

 

[infinity]

Can you just crimp on some adapters like these which go from 600 kcmil to 400 or does the conductor ampacity change?

http://www.cesco.com/b2c/product/NSI-PTO-600-PTO-Series-Offset-Plastisol-Insulated/614892

 

[Npstewart]

Can you just crimp on some adapters like these which go from 600 kcmil to 400 or does the conductor ampacity change?

http://www.cesco.com/b2c/product/NSI-PTO-600-PTO-Series-Offset-Plastisol-Insulated/614892

Ive never seen anything like that before... Im looking into this. As long as those are good for 400A, I dont see why it couldnt be used...

 

[Jraef]

Ive never seen anything like that before... Im looking into this. As long as those are good for 400A, I dont see why it couldnt be used...

That brings up an interesting concept:
When you have an adapter like this, will it be rated for the current capacity of the SMALLER conductor, or the larger one? Common sense says it would be rated for the smaller one if for no other reason than the cross sectional area involved, but prudence would say to rate it for the larger, because there is never a problem with something like this being OVER rated. So since it is so short, could it possibly be rated for the ampacity of 600kCMIL? I would think not, because ostensibly you are terminating into something designed for no more than 400kCMIL, ergo that something would not necessarily be rated for any more than what 400 could carry anyway. In this particular case it's not so clear cut though, because the lug is obviously designed for the current capacity of 4 x 400 cables.

What triggered this is that a) the mfrs literature doesn't mention a current rating, and b) 400kCMIL is rated for 380A at 90C and 3 conductors or more, 335A at 75C. So if you pin down the 600s to 400s, and those pins are rated as 400kCMIL would be, you're going to fall a little short.

Might require a call to the mfr.

 

[qcroanoke]

I think Cummings is nuts.

I've got to go along with that.
You need to call back and talk to someone who has a clue.
Better yet the person that sold you the switch.

 

[qcroanoke]

The only reason why I could see that they may have a point is because there are all these small low voltage connections on the lugs. Each individual lug has a small low voltage connection probably for some type of control wiring . If the lugs were changed, im not sure how this would effect the operation of the switch? Probably send out some type of error message.

Also, this ATS is probably 7 feet tall and 3 feet wide. I really think there is plenty of room although I am asking the electrician to make sure he can actually physically get this done.

If they send you their lugs all those connection points will be available on them. For the life of me I cannot imagine anyone at Onan/Cummings telling you that changing the lugs would violate the UL listing.

 

[Cow]

I'd use those crimp type pin adapters and not think twice about it.

 

[templdl]

I think Cummings is nuts.

I agree. The OEM who supp!ied Cummings the ATS should have optional lugs available. It is strange, maybe not, that the OP did not state if it was a breaker or ASCO type ATS. If it is a breaker type it may be an EATON where an 800a ATS consists of HNC breakers (here we go again guessing as the what the OP has). As such there are TA1201NB1 Al/Cu lugs available for (3) 300-750kcmil.
The only thing to watch for is the room required for bending radius in the enclosure for 600kcmil.

 

[Strathead]

If they send you their lugs all those connection points will be available on them. For the life of me I cannot imagine anyone at Onan/Cummings telling you that changing the lugs would violate the UL listing.

It could be more an issue that the lugs can't be changed in the field without voiding the warranty. I have a Cutler Hammer Elevator disconnect that came in with a dented door. I either needed to send it back or they could send someone out to replace it. I used Bondo because I didn't really feel it was that critical. Anyway, it could be that.

 

[jim dungar]

The OEM who supplied Cummings the ATS should have optional lugs available.

There is an extremely high likelihood that this is actually one of Cummin's own transfer switches, maybe even one from their ONAN line, rather than something from a competitor.

 

[templdl]

There is an extremely high likelihood that this is actually one of Cummin's own transfer switches, maybe even one from their ONAN line, rather than something from a competitor.

I always smile when on OP can be simply answered in one or two replies if only enough details were included in the first place such as the manufacturer of the ATS. But I must admit it does add to the intreque when everyone guesses as to who the manufacturer is.