Time for dedicated outlets!

Jea48, The NEC does not clearly define that and it is left as a design perrogative. It is understood that a dedicated circuit is one where only one appliance will use that circuit. A neutral can be shared but only one appliance per breaker. Some elect to run a neutral for each as a design choice. In either case the neutral is run back to the panel and attached to the neutral bar where all the other neutrals are.

Also you would not connect to a double pole breaker, that is for 240 vac here in the US . They would connect to single pole breakers as they are 120 vac. 

Why eould you not use the bare wire for ground ? That is its intended purpose. In romex each circuit wire has insulation and the ground is bare and all of it is in a protective sleave

cerberus79      17 posts                                        05-06-2017 9:09pm

Also you would not connect to a double pole breaker, that is for 240 vac here in the US . They would connect to single pole breakers as they are 120 vac.

Multiwire branch circuits

A multiwire branch circuit basically consists of two or more ungrounded conductors that share a neutral. All conductors of a multiwire branch circuit must originate from the same panelboard [210.4(A)].

For personnel safety, each multiwire branch circuit must have a means to simultaneously disconnect all ungrounded conductors at its origin [210.4(B)]. If that origin is two or more breakers, you can provide this disconnect by using single-pole circuit breakers with handle ties identified for the purpose [240.15(B)(1)].

http://ecmweb.com/code-basics/branch-circuits-part-1

"single-pole circuit breakers with handle ties identified for the purpose"
The tie used must be a Listed tie for the intended purpose.
Or, just use a 2 pole breaker......
Or, in the case of a 3ph. 4wire multiwire branch circuit a 3 pole breaker.

Just going from memory I believe this was added to the 2008 NEC. After State and local AHJs adopted the new language, at least in my state, the 120V as well as 277V multiwire branch circuit became a thing of the past. I don’t know of anyone that installs them today, or for the last 8 years.

Best regards,
Jim

@cerberus79


Please read the first 36 pages of this white paper.
https://centralindianaaes.files.wordpress.com/2012/09/indy-aes-2012-seminar-w-notes-v1-0.pdf

quote from page 31

The “Conduit Transformer”•

This finally explains what drives 99% of all ground loops!
•Load current in line and neutral produces opposing magnetic fields since instantaneous current flow is in opposite directions
•Imperfect cancellation magnetically induces voltage over the length of the nearby safety ground conductor
•Strongly affected by geometry and proximity of wires
•Highest voltages with randomly positioned wires in conduit
•Lower voltages with uniform geometry of Romex®
•Voltage is directly proportional to load current, wire length, and rate of change in current or ∆I/∆t
•Mechanism favors high-frequency harmonics of 60 Hz
•For constant current in L and N, induced voltage rises at 6 dB/octave

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