2 conductors, 1 lug

[inspector 102]

Can anyone tell me if the neutral lug on a Siemens 400 amp loadcenter is approved for 2 conductors when installed in parralel. Is the lug approved for 2 4/0 CU conductors or is there an accessory lug that needs installed? Am curious to find the listing for this terminal.

 

[bonding jumper]

Re: 2 conductors, 1 lug

All lugs have ratings for ampacity. If you are not overloading a lug, I believe you are allowed to use it up to that rated ampacity. But I'm not certain about this. I would call the manufacturer with the model number and ask them what the ratings are on the lugs. Siemens was nice enough to send my their product catalog on all their electrical so I could look it up, but better to call the manufacturer, 1800-964-4114
Their catalog contains accessories for their load centers and neutral lug kits, model LK3 with wire range #1-300MCM

[ July 15, 2003, 12:42 PM: Message edited by: bonding jumper ]

 

[templdl]

Re: 2 conductors, 1 lug

The lug should be stamped on the side somewhere for number and size of conductors. With a lug of that size if it had only one opening it most likely is good for one cable. The nameplate for the panel may also have a referrence to the number of cables per phase.
If in doubt I would ask for proof to be provided in a document from the manufacturer which list what is allowed. This should easily be be available from a catalog or an instuction leaflet.

 

[vanwalker]

Re: 2 conductors, 1 lug

are there lugs that have this kind of rating, for more than one conductor with only one barrel?THANKS GEO

 

[flightline]

Re: 2 conductors, 1 lug

I would agree with templdl, and add that it may be listed on the label afixed to the interior of the loadcenter. Siemens on their website/catalog states with respect to lugs & terminations:

UL Listed for 60/75oC conductors.
See equipment markings for applications.

Since you stated it must be one of their EQ series loadcenter such as one of those listed here.

If this were one of their P1 panelboards, they DO make 200% neutral lugs and feed-thru neutral lugs, among others. I believe, while range taking the lug you have is for a single conductor termination, [although I've been suprised what manufacturers do these days].

I believe that I have seen certail circuit breakers that do "stack" conductors, and I believe that they were Square D, but they are not predominant in the marketplace, and my memory can be fuzzy at times.

[ July 15, 2003, 05:09 PM: Message edited by: flightline ]

 

[roger willis]

Re: 2 conductors, 1 lug

vanwalker
The answer to your question is YES. There are lugs that are listed for the installation of two conductors in the same barrel.
Roger

 

[tom baker]

Re: 2 conductors, 1 lug

Per the UL panelboard standard, only one grounded (neutral) condcutor is allowed per termination.
This is now in the 2002 NEC:
408.21 Grounded Conductor Terminations.
Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.
Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in a single terminal if the terminal is identified for connection of more than one conductor.

But I'm not sure if the above applies to your installation. What do the instructions say?

[ July 16, 2003, 01:09 PM: Message edited by: tom baker ]