Square D Breaker Mechanical lug

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adityalagudu

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Location
victoria,TX,USA
We need to terminate the 2 runs of 500kcmil cable to the Square D LJA36600U31X Breaker. But the breaker is missing the wire binding screw for the top cable. So currently feasible to install only one cable. Breaker rating is 600A. Tried to use DLO 500 kcmil cable , but the ampacity is also less than 600A and which is 545A. And Square D is saying, we cannot use DLO cables for these lugs. I am trying to purchase the mechanical lug kit CU600LF52K3, but the price and delivery time is high. Need to install these cables ASAP. What would be the best possible solution? View attachment S1A14748 cable installation 1-compressed.pdf
 
electrofelon

electrofelon

Senior Member
Location
Cherry Valley NY, Seattle, WA
DLO cable is not an NEC conductor, unless also marked say RHH (which most modern stuff is). Also the lug is likely not rated for the fine stranding. Use an appropriate connector to transition.

Get a breaker off ebay and steal the set screw from it.
 
Jraef

Jraef

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Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
adityalagudu said:
what do you mean by the appropriate connector to Transition? The breaker is expensive to buy also. Is there any pins that can be used to convert the 2 runs to the single run?
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If you are using fine stranded cable such as DLO/RHH, there are probably no mechanical lugs that you can use for them. The lugs must specifically say on them that they are good for "Class K stranding" or higher. Most set-screw mechanical lugs that come with circuit breakers do not and that data sheet you posted makes no mention of it, you must assume that they are not.

The typical best practice with that type of cable is to get the specially qualified crimp-on lugs for the Class K stranded wire, and then get the bolt / stud optional connector for that breaker. Alternatively there are what are called "pin connectors" that will crimp onto the ends of your cable and give you a Class C stranding stub of wire that will work for your standard mechanical lugs. You must be careful though because some of those that are sold over the internet are not UL listed and that can burn you if inspected.
 
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MrJLH

Senior Member
Location
CO
Jraef said:
If you are using fine stranded cable such as DLO/RHH, there are probably no mechanical lugs that you can use for them. The lugs must specifically say on them that they are good for "Class K stranding" or higher. Most set-screw mechanical lugs that come with circuit breakers do not and that data sheet you posted makes no mention of it, you must assume that they are not.

The typical best practice with that type of cable is to get the specially qualified crimp-on lugs for the Class K stranded wire, and then get the bolt / stud optional connector for that breaker. Alternatively there are what are called "pin connectors" that will crimp onto the ends of your cable and give you a Class C stranding stub of wire that will work for your standard mechanical lugs. You must be careful though because some of those that are sold over the internet are not UL listed and that can burn you if inspected.
Click to expand...

So I would assume Type W cable could not work?
 
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adityalagudu

Member
Location
victoria,TX,USA
You mean terminate both of the cables to the same lug using pin connectors by using qualified crimp on lugs. What is the purpose of a bolt/stud optional connector, how to use them?
 
infinity

infinity

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Location
New Jersey
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I'm going to go out on a limb and say that you're not going to find a viable code complaint solution unless you're willing to fix the actual problem which is the missing set screw on the lug.
 
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jim dungar

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Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
adityalagudu said:
We need to terminate the 2 runs of 500kcmil cable to the Square D LJA36600U31X Breaker. But the breaker is missing the wire binding screw for the top cable. So currently feasible to install only one cable. Breaker rating is 600A. Tried to use DLO 500 kcmil cable , but the ampacity is also less than 600A and which is 545A. And Square D is saying, we cannot use DLO cables for these lugs. I am trying to purchase the mechanical lug kit CU600LF52K3, but the price and delivery time is high. Need to install these cables ASAP. What would be the best possible solution? View attachment 21733
Click to expand...

Why purchase a copper only lug? The standard lug kit is aluminum which is rated for both AL and CU conductors.
They also offer a compression lug kit.
A stud/nut kit is usually used for bus bar connections.

But as others have mentioned, the fine stranding needs to be considered.
 
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