Wiring a switch

[charles p]

I was taught to take the black wire to the switch so the light socket would not be hot when the switch was off.  I've since read that you can do it with the white or black, depending on where the switch is located in the circuit.

What does the electrical code say?  Which way do you prefer?

[PowPow]

Black is hot (from the circuit breaker or fuse)
White is neutral, i.e, no voltage to ground but it carries current that could zap you if you got in series with it (not hard to do).
Green is earth ground; supposed to be no voltage or current, just a safety wire.

If you will wire black to the switch and to the light, the next person who comes behind you will know what to expect.
If you keep your white wire as solid as possible, i.e, few splices, you will reduce the hazard of getting in series with it.

In your example of wiring the switch through the white wire, the whole appliance and half the switch is energized relatve to ground with the switch off; a person in contact with the ground could get electrocuted while changing the light bulb.

Disclaimer: Electrical work should be performed only by a licensed electrician following local codes.

[mechanic]

The ONLY time it's proper to break anything but  the black wire through  the switch is when you are using 3 way or 4 way switches, where 2 or more switches control the same light.....and that's a different subject entirely.  Pow Pow is correct, to do otherwise endangers someone.  If you were to have a defective lamp, etc. you could cause injury or death.  Don't do it!

Ben

[Drilling Man]

Black is hot (from the circuit breaker or fuse)
White is neutral, i.e, no voltage to ground but it carries current that could zap you if you got in series with it (not hard to do).
Green is earth ground; supposed to be no voltage or current, just a safety wire.

If you will wire black to the switch and to the light, the next person who comes behind you will know what to expect.
If you keep your white wire as solid as possible, i.e, few splices, you will reduce the hazard of getting in series with it.

In your example of wiring the switch through the white wire, the whole appliance and half the switch is energized relatve to ground with the switch off; a person in contact with the ground could get electrocuted while changing the light bulb.

Disclaimer: Electrical work should be performed only by a licensed electrician following local codes.

  +1

  DON'T DO IT!

  DM

[Doug B.]

Let's all keep in mind that what has been mentioned relates to code. One NEVER knows just how somebody before you may have bubba'd something, unless they knew what they were doing! I find it more comforting to use some sort of voltage detecting instrument to find the load or hot wire before i begin. This does reduce my chances of getting zapped.

[SHOOTALL]

People often use the white as a runner to a switch . When you do its normal to put black tape on it where it attaches to the switch and divice to mark it as hot

[Glanceblamm]

People often use the white as a runner to a switch . When you do its normal to put black tape on it where it attaches to the switch and divice to mark it as hot

Ditto, and meets the code.

[CannonKrazy]

People often use the white as a runner to a switch . When you do its normal to put black tape on it where it attaches to the switch and divice to mark it as hot

Ditto, and meets the code.

You both are correct.

[mechanic]

Bear in mind fella's that the NEC is not the only code to meet.  Local codes also come into play.  Here in my area, I had to use 4 wire to my service, 4 wire to major appliances, and then bond neutral to ground in the panel.

Any neutral through a switch here thats caught by inspection will fail.

[SHOOTALL]

Thought the NEC included the 4 wire to range , dryer etc now ?

[mechanic]

Thought the NEC included the 4 wire to range , dryer etc now ?

I believe you are correct, but this is the first time I've had to run 4 wire service entrance, and THEN bond neutral to ground in the box.  Kinda' makes the 4th wire useless IMO, but that's what was required. 

Just below where I live, an 8 foot ground rod won't pass, must dig an 18" deep trench 32' long and bond 4 rods in the trench....(local standards).

[SHOOTALL]

Here if ground conditions exist you can bury a rod horz in the ground , like hitting rock. And also in places you may need multi rods . Its in the code under local conditions .

[elmer]

Thought the NEC included the 4 wire to range , dryer etc now ?

I believe you are correct, but this is the first time I've had to run 4 wire service entrance, and THEN bond neutral to ground in the box.  Kinda' makes the 4th wire useless IMO, but that's what was required. 

Just below where I live, an 8 foot ground rod won't pass, must dig an 18" deep trench 32' long and bond 4 rods in the trench....(local standards).

As I understand it, the reason for requiring a neutral on 220 outlets now is because appliance manufacturers sometimes have 110V devices such as timers and were using ground for return which is a NO NO.