240.20(a)-connected in series

[ekimk]

Scenario- An existing panel with a conductor exiting the top via conduit to supply wall receptacle outlet, and another conductor ran from bottom of panel within a slab conduit emerging within a second wall to supply another receptacle. Both conductors have been terminated under a single pole 20a breaker. I make reference to 240.20(a) disallowing use because the circuit breaker is not connected in series with each ungrounded conductor. I have always thought the implications for faults, short circuits in individual ocp devices are impaired when the connection has not been made in series, and another path exists at the supply.

Previously mentioned in a (1-4-2k) Question & answer code quandary "The only time two wires can be installed under a single screw or lug is when the terminal is identified for this purpose. Circuit breakers rated not more than 30 ampers are often identified for the termination of two conductors. This can be verified by reviewing the circuit breaker manufacture's catalog".

I would like to keep this separate from 240.21, as I understand tap implications. This "doubling-up" of breaker terminations is a bad practice and blows the tap rule out the window anyway.

What am I missing that would allow double lugging wires under a circuit breaker? What does 240.20(a) really mean?

Thanks for all that you contribute to the industry. I am looking forward to your reply.

 

[Dennis Alwon]

I do not consider 2 wires under one breaker a tap. It would be no different if the two conduits came together in a junction box and one wire run down to the panel. If the breaker is listed for two conductors if not, then splice the two wires in the panel and pigtail a short piece to the breaker.

 

[iwire]

I do not consider 2 wires under one breaker a tap.

I agree.

240.2 gives the definition of a 'tap conductor' as it is used in Article 240.

Assuming the ampacity of both conductors supplied by that breaker matched or exceeded the breakers rating they would not be taps.

 

[bphgravity]

Read the definition of TAP at the beginning of Article 240.

240.20(A) simply means you are required to have an overcurrewnt device in series with the circuit source and circuit conductors.

Your overthinking the whole issue...

 

[ekimk]

Thanks to all. I was possibly overthinking. In many existing occupancies there are many more unlisted breakers that have doubled up terminations than those that do not. The tap was not the issue as much as my insistence to read into "a fuse or overcurent trip unit of a circuit breaker shall be connected in series with EACH ungrounded conductor." Therefore, I, by golly was not going to let you double up.
Serve my slice warm please.

 

[LarryFine]

I have always thought the implications for faults, short circuits in individual ocp devices are impaired when the connection has not been made in series, and another path exists at the supply.

This is another pathway from the supply, not a second supply to a load.