60A circuit breaker with two feeders

[dahualin]

I am trying to use one 60A circuit breaker in MDP to feed two disconnect. Can I connect two wires to one circuit breaker terminal? If I can, what I shall pay attention to? Thanks.

 

[Dennis Alwon]

I am trying to use one 60A circuit breaker in MDP to feed two disconnect. Can I connect two wires to one circuit breaker terminal? If I can, what I shall pay attention to? Thanks.

I doubt that you can hook 2 wires to one terminal on a CB. I would install a jb outside the panel and splice them. You can if room permits splice the wires in the panel and have one wire on each terminal of the breaker.

 

[infinity]

What size conductors are you proposing to use?

As Dennis said it's highly unlikely that a 60 amp CB will be rated for 2 conductors. Having said that there are many other design options but those would require more information.

 

[weressl]

I doubt that you can hook 2 wires to one terminal on a CB. I would install a jb outside the panel and splice them. You can if room permits splice the wires in the panel and have one wire on each terminal of the breaker.

Since the terminals are designed to accomodate stranded wires that are nothing else but multiples of smaller wires, there is no reason why you would not be able to use multiple cables consisting of strands of the same size. You have to make sure that you do not exceed the maximum equivalent wiresize that the MCB terminal is listed for. Circuit breakers are often available with optional terminals of various configuration.

Remember: "we always did it that way" is far from sound reasoning.....

 

[iwire]

Since the terminals are designed to accomodate stranded wires that are nothing else but multiples of smaller wires, there is no reason why you would not be able to use multiple cables consisting of strands of the same size.

No reason.....other then the NEC violation you would create.

 

[infinity]

No reason.....other then the NEC violation you would create.

I concur, reminds me of what guys used to do when the panel didn't have an EGC bar. Just twist 20 or 30 EGC's together and fit into a big lug bolted to the panel. Wasn't legit then, still isn't.

 

[jrannis]

No reason.....other then the NEC violation you would create.

Which would be.......... drum roll.......

 

[iwire]

Which would be.......... drum roll.......

110.3(B) and 110.14.

 

[Dennis Alwon]

Which would be.......... drum roll.......

Also many breakers will specify the wire size allowed. Putting 2 wires under the lug, even if the sum were less than the size specified would still be a violation. A 60 amp breaker is good for #6 or maybe #4. Two #8's would be less than the cir. mil of one #4 but it could be a violation if the breaker does not specify that it is rated for 2 wires. I hear whar weressl is getting at but I don't think it would fly. Why not just splice the wire and be done with it?

 

[Southpaw]

Splicing in Panelboard

Splicing in Panelboard

Check with your electrical inspector to see if they permit splices in panelboards before you execute the work.

Technically this is not kosher as I am not aware of panelboards listed for splices.

However many electrical inspectors permit this.

I personally don't see the problem with splicing in the panelboard but I have worked with several that had strong feelings that this was not permitted. My 100 year old house's home new panelboard was rewired this way, prior to my owning it and it was approved by the electrical inspector

 

[iwire]

Check with your electrical inspector to see if they permit splices in panelboards before you execute the work.

Technically this is not kosher as I am not aware of panelboards listed for splices.

The NEC allows splices in panel boards and using panel boards as raceways, check out 312.8 but be sure to read the whole section, not just the first sentence.

 

[peter d]

I personally don't see the problem with splicing in the panelboard but I have worked with several that had strong feelings that this was not permitted.

I've never understood this. How is a splice in a panel any different than a splice in a 4" square?

 

[weressl]

110.3(B) and 110.14.

It is NOT a violation of the code IF the CB meets these conditions.

110.3 (B) Installation and Use.​

​

​

Listed or labeled equipment
shall be installed and used in accordance with any instructions
included in the listing or labeling.

110.14.(A).....Terminals for more than one conductor and terminals
used to connect aluminum shall be so identified.​

 

[iwire]

It is NOT a violation of the code IF the CB meets these conditions.

Of course, we even talked about that in this vey thread. :smile:

We also mentioned that it would be a very rare 60 amp circuit breaker that had single terminals rated for more then one 6 AWG.

It just a cover your rear code thing, I agree with your thought here..

Since the terminals are designed to accomodate stranded wires that are nothing else but multiples of smaller wires, there is no reason why you would not be able to use multiple cables consisting of strands of the same size.

It just comes down to being listed for that use. :smile:

 

[weressl]

Of course, we even talked about that in this vey thread. :smile:

We also mentioned that it would be a very rare 60 amp circuit breaker that had single terminals rated for more then one 6 AWG.

It just a cover your rear code thing, I agree with your thought here..

It just comes down to being listed for that use. :smile:

That is exactly right. In my original response I have NOT addressed the Code issue at all, just the engineering principles and their underlying physics as how the questions arise from the application can be answered.

Interestingly enough, terminals that are constructed IDENTICAL to the standard CB lugs ARE designed and approved for terminating two, but not more than two, wires.

http://eshop.phoenixcontact.com/phoenix/treeViewClick.do?UID=3044076&parentUID=852325634&reloadFrame=true

(These are rated to 415A)

Just as an excercise, if you interested parttaking in it, walk up to a number of CB panels, both residential, industrial and commercial and report back to us how many small branch circuit panels you find where is NO doubled-up wires under at least one circuit breaker.

 

[Dennis Alwon]

Just as an excercise, if you interested parttaking in it, walk up to a number of CB panels, both residential, industrial and commercial and report back to us how many small branch circuit panels you find where is NO doubled-up wires under at least one circuit breaker.

Sure we see that all the time I have never seen one fail however, ever inspection report from a home inspector comes back with a statement to remove the double wires. Try proving that a 50 year old panel is rated for 2 wires under the breakers.

 

[iwire]

Just as an excercise, if you interested parttaking in it, walk up to a number of CB panels, both residential, industrial and commercial and report back to us how many small branch circuit panels you find where is NO doubled-up wires under at least one circuit breaker.

I don't have to, I have been seeing it for all my time in the trade. :smile:

It matters not.

The fact that it will work matters not.

The agreement with the states that I am licensed in requires I follow the NEC, even when I think I know better. :smile:

It does not have to make sense.......it just has to meet code....and be safe.

 

[weressl]

I don't have to, I have been seeing it for all my time in the trade. :smile:

It matters not.

The fact that it will work matters not.

The agreement with the states that I am licensed in requires I follow the NEC, even when I think I know better. :smile:

It does not have to make sense.......it just has to meet code....and be safe.

...and I think it demonstrates that sometimes the Code has NOTHING to do with safety, just arbitrariness. The problem with that is that the people who apply the Code in practice will not develop a valid sense of danger. When they see that misapplication of the Code does not result in any danger, they will relax in rigorously following every word of the Code. That will result in being lax in areas where one can not. That in turn will result even more restrictions being written into the Code such as the AFCI and wider and wider application of the GFCI's.

 

[BryanMD]

...and I think it demonstrates that sometimes the Code has NOTHING to do with safety, just arbitrariness.

In principle, I agree 100%.

The problem with that is that the people who apply the Code in practice will not develop a valid sense of danger.

The "problem" is the people who "apply the code" are tradesmen but are NOT engineers. All tradesmen are not trained equal.

Recognizing this reality is a large part of why there are codes.

When they see that misapplication of the Code does not result in any danger, they will relax in rigorously following every word of the Code. That will result in being lax in areas where one can not.

Agreed.

That in turn will result even more restrictions being written into the Code such as the AFCI and wider and wider application of the GFCI's.

Now we're getting into the juicy part!

 

[iwire]

...and I think it demonstrates that sometimes the Code has NOTHING to do with safety, just arbitrariness.

But....that is no excuse for either tradesmen or engineers ignoring the rules when they think they are smarter then 100+ years of code development.

If the rules are wrong work to change them, but until they change follow them. :smile: