Problems with 300.20(A)

[mgookin]

300.20 Induced Currents in Ferrous Metal Enclosures
or Ferrous Metal Raceways.
(A) Conductors Grouped Together. Where conductors carrying alternating current are installed in ferrous metal enclosures or ferrous metal raceways, they shall be arranged so as to avoid heating the surrounding ferrous metal by induction. To accomplish this, all phase conductors and, where used, the grounded conductor and all equipment grounding conductors shall be grouped together.

300.20 Induced Currents in Ferrous Metal Enclosures
or Ferrous Metal Raceways.
(A) Conductors Grouped Together. Where conductors carrying alternating current are installed in ferrous metal enclosures or ferrous metal raceways, they shall be arranged so as to avoid heating the surrounding ferrous metal by induction. To accomplish this, all phase conductors and, where used, the grounded conductor and all equipment grounding conductors shall be grouped together.

That part does not require anything. It only says "when they are installed, then..."

300.20 Induced Currents in Ferrous Metal Enclosures
or Ferrous Metal Raceways.
(A) Conductors Grouped Together. Where conductors carrying alternating current are installed in ferrous metal enclosures or ferrous metal raceways, they shall be arranged so as to avoid heating the surrounding ferrous metal by induction. To accomplish this, all phase conductors and, where used, the grounded conductor and all equipment grounding conductors shall be grouped together.

And this part says what to do if they are "... installed in..."

The way I read that, no neutral is ever required. But if you have a neutral, then arrange them...

 

[electricalist]

If the neutral were required would that be, if in emt 1 hot /1 neutral coming down then 1 hot / 1 neutral back up which leads to a j box where the neutrals are..seperated or all tied together.
Or just 1 neutral coming down.

Sent from my GT-N5110 using Tapatalk

 

[infinity]

If 300.20(A) required the neutral to be brought to a switch, then why did they add 404.2(C) to the 2011 code?

In my opinion language permitting switch loops needs to be added to 300.20(A), because some inspectors don't understand physics. I'm dealing with this right now in one jurisdiction and it infuriates me.

I agree and I brought this up for that exact reason when the party involved cited 300.20(A) and 300.3(B) "where used" as the neutral being required to looped through the switch. After they showing this to several other people who were involved they agreed that it was required. I argued that we've been wiring single pole switches for 100 years with only two conductors (switch loop) being brought down to the switch and no one seemed to question the physics involved.

Thanks for the opinions, my head is finally screwed back on straight regarding the meaning of "where used" as it applies to these installations.

 

[kwired]

Ha. There go three of us posting about 404.2(C) within minutes of each other.

Art 404 doesn't apply to this lighting contactor anyway does it?

The primary intention of 404.2(C) is pointed out in the informational note that follows it:

"The provision for a (future) grounded conductor is to complete a circuit path for electronic lighting control devices."

This section is intended for typical wall switch applications, not for a lighting contactor that likely already has some automation method driving it.

 

[iwire]

Art 404 doesn't apply to this lighting contactor anyway does it?

The primary intention of 404.2(C) is pointed out in the informational note that follows it:

"The provision for a (future) grounded conductor is to complete a circuit path for electronic lighting control devices."

This section is intended for typical wall switch applications, not for a lighting contactor that likely already has some automation method driving it.

The fact it does not directly apply to contactor does not in the least change the point made.

 

[jumper]

Art 404 doesn't apply to this lighting contactor anyway does it?

The primary intention of 404.2(C) is pointed out in the informational note that follows it:

"The provision for a (future) grounded conductor is to complete a circuit path for electronic lighting control devices."

This section is intended for typical wall switch applications, not for a lighting contactor that likely already has some automation method driving it.

Infinity had a second question in his OP:

Also what in the code would specifically allow the use of a two wire switch loop without the neutral being run down to the switch with the ungrounded conductors? For example I have a 200' run of EMT for a SP switch, that raceway would typically have only two conductors, a hot leg and a switch leg.

We all ignored the contactor and answered that.