Hypothetical Question on Switch Loops

[exranger06]

Another thread here put this thought in my head: So, I know that every switch box now needs a neutral present (with some exceptions). Therefore, running a switch loop the "old fashioned way" by using a 2-conductor cable and putting some black tape on the white conductor is no longer permissible.

Also, if you had a 3-gang box with 3 switches, and the switches were on 3 different circuits, you would need 3 separate neutral wires (one for each circuit). I understand all of that.

However, if you had a 3-gang box with 3 switch loops ran to it, and all 3 switches were on the SAME circuit, would you still need 3 separate neutral wires entering the box? Could you run just one 3-conductor cable for one switch loop, and run the other 2 switch loops with 2-conductor cable the "old fashioned way?" You'd still have a neutral present in the box that you could potentially hook up to all 3 switches since they're all on the same circuit.

Again, totally hypothetical. I tried searching to see if that's permissible but couldn't find the answer.

 

[Norcal]

As long as they are all switching lights on the same circuit, I see no reason why not. The reason for the neutral being required to be available is for occupancy sensors, the load is small but it is a bad practice to interconnect neutrals from different circuits.

 

[Raisedonadeere]

As long as they are all switching lights on the same circuit, I see no reason why not. The reason for the neutral being required to be available is for occupancy sensors, the load is small but it is a bad practice to interconnect neutrals from different circuits.

Could you elaborate on "Occupancy sensors?"

 

[rlitman]

...The reason for the neutral being required to be available is for occupancy sensors...

Or WiFi switches, or smart dimmers, some LED compatible timer switches, or any switches that require a neutral to draw power to do something internal, because they are no longer supposed to put a parasitic load through incandescent bulb elements.

 

[CoogarXR]

Or WiFi switches, or smart dimmers, some LED compatible timer switches, or any switches that require a neutral to draw power to do something internal, because they are no longer supposed to put a parasitic load through incandescent bulb elements.

Yeah, I tried to put an occupancy sensor in my shed on an old-school switch loop, and my lights stayed dimly lit from the sensor drawing power through them when in standby.

 

[wyliesdiesels]

Could you elaborate on "Occupancy sensors?"

aka a motion sensor in place of a snap switch

 

[MattT]

As long as they are all switching lights on the same circuit, I see no reason why not. The reason for the neutral being required to be available is for occupancy sensors, the load is small but it is a bad practice to interconnect neutrals from different circuits.

It's worse than bad practice. You get an open neutral on one of the circuits and all the current is going to flow thru' the other one. This happens with two heavily loaded circuits on the same hot leg and you've got a fire.

It can also cause nuisance tripping on GFI protected circuits and might do on CAFI circuits too.