Lug ratings

[arnettda]

I have a 600 amp disconect and the lug rattings on the door are as follows.
(2) 1/0Awg-750kcmil
(4) 1/0AWG-250KCMIL

Which means I can put three 250mcm wires under one lug? I have never done this and want to double check. I thought the hole in lugs that took more than one wire was oblong and not round and these lugs are round. This would also mean I can not put just one wire under these lugs?
Thanks

 

[Dennis Alwon]

I have no idea what that means but it doesn't make sense. How can the lugs be both 1/0-750 and 1/0 thru 250. Are you sure the (2) and (4) aren't numbers that refer to a lug on the diagram rather than the number of wires.

I have never seen a lug that would hold more than 1-1/0 wire unless it was a double lug

 

[arnettda]

I have no idea what that means but it doesn't make sense. How can the lugs be both 1/0-750 and 1/0 thru 250. Are you sure the (2) and (4) aren't numbers that refer to a lug on the diagram rather than the number of wires.

I have never seen a lug that would hold more than 1-1/0 wire unless it was a double lug

I do not exactly remeber how it was stated but it was on a chart and I believe it said line load and neutral lugs. And then (2) 1/0awg-750kcmil
(4) 1/0awg-250kcmil was below that.

 

[Dennis Alwon]

I do not exactly remeber how it was stated but it was on a chart and I believe it said line load and neutral lugs. And then (2) 1/0awg-750kcmil
(4) 1/0awg-250kcmil was below that.

Something does not sound correct. Take a picture of it when you can

 

[SG-1]

Sounds like the lug is suitable for use with the conductor size listed, 1/0 through 750kcmil. You can only use one conductor in the listed range because the hole is round. Choose your conductor well.

 

[GoldDigger]

I do not exactly remeber how it was stated but it was on a chart and I believe it said line load and neutral lugs. And then (2) 1/0awg-750kcmil
(4) 1/0awg-250kcmil was below that.

Possibly it was indicating that there were a total of six lugs, two of which (line?) could accept up to 750 and four (load and two neutrals?) which could only handle up to 250? But only one wire each.

 

[infinity]

I agree with Dennis without a photo we're all just guessing but something doesn't seem right. What is the brand of the disconnect switch?

I've seen lugs rated for two conductors but never four. This one is clearly labeled for two conductors:

 

[jimport]

I suspect the lugs are labeled in the diagram as either part number 2 or 4.

 

[weressl]

I have a 600 amp disconect and the lug rattings on the door are as follows.
(2) 1/0Awg-750kcmil
(4) 1/0AWG-250KCMIL

Which means I can put three 250mcm wires under one lug? I have never done this and want to double check. I thought the hole in lugs that took more than one wire was oblong and not round and these lugs are round. This would also mean I can not put just one wire under these lugs?
Thanks

It means that on the disconnect tabs you can put 2 lugs/phase of 1/0(min)-750kCMil(max) RANGE, or 4 lugs/phase of 1/0(min)-250kCMil(max) RANGE. Normally the disconnects do not come with lugs attached, unless specified, and if it came with lugs then you have to CHECK the actual lugs what the min/max size THAT lug can accept.

 

[Dennis Alwon]

It means that on the disconnect tabs you can put 2 lugs/phase of 1/0(min)-750kCMil(max) RANGE, or 4 lugs/phase of 1/0(min)-250kCMil(max) RANGE. Normally the disconnects do not come with lugs attached, unless specified, and if it came with lugs then you have to CHECK the actual lugs what the min/max size THAT lug can accept.

That would make sense. :thumbsup:

 

[arnettda]

It means that on the disconnect tabs you can put 2 lugs/phase of 1/0(min)-750kCMil(max) RANGE, or 4 lugs/phase of 1/0(min)-250kCMil(max) RANGE. Normally the disconnects do not come with lugs attached, unless specified, and if it came with lugs then you have to CHECK the actual lugs what the min/max size THAT lug can accept.

I like that. I was back there today. It came with lugs and there were two sets of lugs on each phase and 4 lugs on the neutral bar. I need to replace phase lugs so there are three of them. So I need to keep lug size max to 250mcm. Does it come down to amount of contact the lug makes with the bus? I need to figure out how to get pictures from my phone to here.

 

[eHunter]

I like that. I was back there today. It came with lugs and there were two sets of lugs on each phase and 4 lugs on the neutral bar. I need to replace phase lugs so there are three of them. So I need to keep lug size max to 250mcm. Does it come down to amount of contact the lug makes with the bus? I need to figure out how to get pictures from my phone to here. [/QUOTE]

Helpful hints posting pictures is close to the bottom of this post:

http://forums.mikeholt.com/showthread.php?t=81328