I WANT TO YELL

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petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I ordered some 400A breakers for use on 200HP VFDs. (2) 1/0 or (1) 350 are the best choice wire sizes for me.

The CBs come with two hole lugs.

Wire range - 3/0 to 250.

Going to 3/0 from 1/0 is pricey, so I am just going to take off the existing lugs and buy some new ones.

Of course, I personally will not be doing it.

The shop has to remove the line lugs anyway so we can use some flex cable to wire to the VFDs.

What am I going to do with (84) 2 hole lugs sized for 3/0-250?
 

kwired

Electron manager
Location
NE Nebraska
I ordered some 400A breakers for use on 200HP VFDs. (2) 1/0 or (1) 350 are the best choice wire sizes for me.

The CBs come with two hole lugs.

Wire range - 3/0 to 250.

Going to 3/0 from 1/0 is pricey, so I am just going to take off the existing lugs and buy some new ones.

Of course, I personally will not be doing it.

The shop has to remove the line lugs anyway so we can use some flex cable to wire to the VFDs.

What am I going to do with (84) 2 hole lugs sized for 3/0-250?

You will put them on a shelf and forget about them and someday you will order something similar because you forgot you had them:happyyes:
 

templdl

Senior Member
Location
Wisconsin
This happens so often. Often times the number of wires and the wire sizes are not consider when ordering breakers. The breaker is installed and then it is discovered that the wire that has been pulled is not capable of being terminated on the lugs as supplied. Larger breakers often have a number of lug options available if they are specified.
One word of caution, you weren't specific but eluded to the use of a special cable which I might interpret as being fine stranded such as hypalon. If so you may want to consider using ring tongue crimp on terminals that are listed for the termination that you select to terminate the wire and bolt them to the breaker. Also consider using Nonmagnetic bolt and nut to reduce the chances of heating.
The fine stranded hypalon wire is with almost all certainty not UL listed for use with terminals that a commonly supplied with breakers.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
This happens so often. Often times the number of wires and the wire sizes are not consider when ordering breakers. The breaker is installed and then it is discovered that the wire that has been pulled is not capable of being terminated on the lugs as supplied. Larger breakers often have a number of lug options available if they are specified.
One word of caution, you weren't specific but eluded to the use of a special cable which I might interpret as being fine stranded such as hypalon. If so you may want to consider using ring tongue crimp on terminals that are listed for the termination that you select to terminate the wire and bolt them to the breaker. Also consider using Nonmagnetic bolt and nut to reduce the chances of heating.
The fine stranded hypalon wire is with almost all certainty not UL listed for use with terminals that a commonly supplied with breakers.

The line wires have to be regular wire (class B or C) because the other end is a connector that is only good for regular wire.

I want to switch to fine stranded on the load side because it will be a lot easier to route for our shop. So, I was going to just use some panduit compression lugs for flex cable and run (2) 1/0 from the CB to the drives.

It turns out the stud on the drive is only sized to allow a single lug and if you want to use two wires you have to buy an AC Terminal Extension Kit. I kid you not. I went out to look at the drive a few minutes ago and I am suspicious that two compression lugs will not fit on the stud. It is dark out in our shop right now, so I can't see real well. I will have to have them take the nut off and see just how much room there is.

In any case, I will probably just reuse the existing bolt on the CBs.
 

templdl

Senior Member
Location
Wisconsin
The line wires have to be regular wire (class B or C) because the other end is a connector that is only good for regular wire.

I want to switch to fine stranded on the load side because it will be a lot easier to route for our shop. So, I was going to just use some panduit compression lugs for flex cable and run (2) 1/0 from the CB to the drives.

It turns out the stud on the drive is only sized to allow a single lug and if you want to use two wires you have to buy an AC Terminal Extension Kit. I kid you not. I went out to look at the drive a few minutes ago and I am suspicious that two compression lugs will not fit on the stud. It is dark out in our shop right now, so I can't see real well. I will have to have them take the nut off and see just how much room there is.

In any case, I will probably just reuse the existing bolt on the CBs.

Great, it looks like you have it under control. You wouldn't believe how many electricians and technicians disregard wire types and what can and can not be used with a mechanical lug.
I would be concerned with (2) lugs on a stud unless you can confirm that the lugs a UL listed to do so. I would be concerned about heat rise on the termination.
 

Smart $

Esteemed Member
Location
Ohio
The shop has to remove the line lugs anyway so we can use some flex cable to wire to the VFDs.

The line wires have to be regular wire (class B or C) because the other end is a connector that is only good for regular wire.

I want to switch to fine stranded on the load side because it will be a lot easier to route for our shop. So, I was going to just use some panduit compression lugs for flex cable and run (2) 1/0 from the CB to the drives.
Did you mean load in the OP?

Perhaps not applicable for this particular installation, but check out page 31 of this publication: http://www.greaves-usa.com/pdf/PAGE 23 - 40 3 29 07.pdf
 

templdl

Senior Member
Location
Wisconsin
The line wires have to be regular wire (class B or C) because the other end is a connector that is only good for regular wire.

I want to switch to fine stranded on the load side because it will be a lot easier to route for our shop. So, I was going to just use some panduit compression lugs for flex cable and run (2) 1/0 from the CB to the drives.

It turns out the stud on the drive is only sized to allow a single lug and if you want to use two wires you have to buy an AC Terminal Extension Kit. I kid you not. I went out to look at the drive a few minutes ago and I am suspicious that two compression lugs will not fit on the stud. It is dark out in our shop right now, so I can't see real well. I will have to have them take the nut off and see just how much room there is.

In any case, I will probably just reuse the existing bolt on the CBs.

Great, it looks like you have it under control. You wouldn't believe how many electricians and technicians disregard wire types and what can and can not be used with a mechanical lug.
I would be concerned with (2) lugs on a stud unless you can confirm that the lugs a UL listed to do so. I would be concerned about heat rise on the termination.
 

jaylectricity

Senior Member
Location
Massachusetts
Occupation
licensed journeyman electrician
I don't have the answer to your question, so I'll just add my own reason to yell. Notice I didn't use capital letters.

I purchased 40 feet of #1 CU for a water ground when I only needed #4.

I wasted enough money to buy myself dinner and a beer at a franchise restaurant such as Peachhornets or Bluejays (names have been changed to preserve the sanctity of this site).
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Great, it looks like you have it under control. You wouldn't believe how many electricians and technicians disregard wire types and what can and can not be used with a mechanical lug.
I would be concerned with (2) lugs on a stud unless you can confirm that the lugs a UL listed to do so. I would be concerned about heat rise on the termination.

the stud does not carry any current. it is just there to hold the lugs in place.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Did you mean load in the OP?

Perhaps not applicable for this particular installation, but check out page 31 of this publication: http://www.greaves-usa.com/pdf/PAGE 23 - 40 3 29 07.pdf

I did.

We have used the greaves pin adapters for flex cable before but they are pricey - like $60 each for #4 sized pins, and they are not listed either.

I may end up being forced into using regular wire to the vfds and buying some two barrel mechanical lugs. 1/0 is not that bad to bend.

The whole flex cable thing started because the shop manager said we had a whole roll of 2/0 flex that he wanted to use up. It turns out it is only about 250 feet and is really 3/0, so there is not enough of it anyway. I saw what looked like it might be 350 flex though out in the stockroom yesterday. it was dark so I am not sure, but there might be enough of it to run from the CB down to the VFD using compression lugs.
 
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