DIY Home Improvement Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter #1
I am wiring a room with 3 lights and 3 switches. The diagrams I have been using have the neutral wire bypass the switches, so only hit and ground are connected to the switch. I have read both ways of doing this, is hot and ground only the correct way? Thanks!

Background:
12/2 wire on a 15 amp breaker to switch 1.
630954
 

·
Registered
Joined
·
1,632 Posts
Switches need always-hot (black) and switched-hot (dotted black, though I prefer red).

Switches do not need neutral at all. Neutral should bypass the switch as per the diagram.

Switches only need ground if the junction box is not metal. If it is, you must attach the ground wire to the metal box no matter what. The switch will pick up ground via its screws and the metal box.

Your diagram does not show a "switch loop". If you are doing a switch loop, then you need to bring neutral to it, so you need /3 cable.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #3
Switches need always-hot (black) and switched-hot (dotted black, though I prefer red).

Switches do not need neutral at all. Neutral should bypass the switch as per the diagram.

Switches only need ground if the junction box is not metal. If it is, you must attach the ground wire to the metal box no matter what. The switch will pick up ground via its screws and the metal box.

Your diagram does not show a "switch loop". If you are doing a switch loop, then you need to bring neutral to it, so you need /3 cable.
Thanks. I am not doing a switch loop.. the "switched hot" , can that be the black wire in the romex going from the switch to the light? I currently have it roughed in with a 12/2 wire from the breaker to the switch box, a 12/2 from the switch box to the next switch box and a 3rd 12/2 from the switch box to the light box.
 

·
Registered
Joined
·
3,971 Posts
Your diagram is the preferred way of doing it. It keeps the circuit simple and put a neutral in the J-box which is now required by code.....for some time.
But using 14 ga. wire would have made it easier to make the connections.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #5
Your diagram is the preferred way of doing it. It keeps the circuit simple and put a neutral in the J-box which is now required by code.....for some time.
But using 14 ga. wire would have made it easier to make the connections.
Yes..I have realized already the 12/2 was a bit much! The boxes are all plastic, so I'll add a pigtail on the ground to the switch as well as the lights. Thanks
 

·
Super Moderator
Joined
·
20,956 Posts
A switch loop is power to the fixture first and you run 2 wire cable to the switch. Power goes to the switch on the white and comes back switched on the black. It is a loop and there is no neutral.
 

·
Registered
Joined
·
25 Posts
Discussion Starter #8
A switch loop is power to the fixture first and you run 2 wire cable to the switch. Power goes to the switch on the white and comes back switched on the black. It is a loop and there is no neutral.
So when I run power to the switch first, I can use a 12/2 wire from the switch to the light and that black wire will act as the "switched hot"? Thanks
 

·
Licensed electrician
Joined
·
13,405 Posts
The outgoing black from the switch would be the switched hot.
 
  • Like
Reactions: ejs82

·
Registered
Joined
·
2,803 Posts
So with just the line ana switched hot in the switch bos, how do you install the new tangled smart switches you control with your phone, most of which seem to need a neutral?
 

·
A "Handy Husband"
Joined
·
11,845 Posts
With a 15 amp breaker you only need #14 .

Sent from my moto g power using Tapatalk
 

·
Licensed electrician
Joined
·
13,405 Posts
The smart switches needing a neutral drove the code change for neutrals in a switch location.
 

·
Licenced Electrician
Joined
·
370 Posts
There have been electronic devices requiring a neutral around for decades. The current crop of smart switches, timers and digital dimmers, all relatively inexpensive, gave the code that extra push, yes.
 

·
Registered
Joined
·
9,036 Posts
RE: switch loops
631257

The middle diagram no longer meets code but may be grandfathered.
In all cases the wire going to the hot terminal of the light may not be the white one even if marked at the ends with black tape.

<<< So with just the line and a switched hot in the switch box, how do you install the newfangled smart switches you control with your phone, most of which seem to need a neutral? >>>

Don't try this at home. Well ... some folks used the equipment grounding conductor (not shown above) for a neutral.

You would have to string new wiring, for example 12-3 Romex, down to the switch box. Or choose a model of smart switch, timer, etc. which used a battery for internal power.
 
1 - 14 of 14 Posts
Top