Shop Electrical

[burninbriar]

But wouldn’t it be red & black to power, white to the common bus bar, and green to the ground bus bar?

I hope I don't get in trouble here, I'm not an electrician so don't take my stuff to the bank.
120 and 240 both use two wires to complete the circuit and one wire for safety to trip a breaker in case of an electrical short. 120 uses one hot (black) and neutral (white) to complete the circuit and 240 uses two hots out of phase (black & red or any color but white or green) to complete the circuit. That just leaves the safety ground to deal with.

[Bob Kraemer]

If the cable is 12/2 w/gnd you are allowed to identify the white conductor with a permanent marker or black tape to be used as phase conductor only if it part of a cable assembly IE: romex, MC cable BX etc!
If the wires are installed in conduit you are not allowed to do this, with the exception being the conductors are over #6 awg.
But as the others stated the inspector has jurisdiction over what the code says.

[fun4now]

i would call the inspector and ask him if he will alow you to paint the white wire ? be it with permanent marker or paint, if he goes for it great if not best to just bite the bullet and get the wire he wants.
white wires are used as hots in switch loops all the time so it can be done it just depends on what the inspector wants to alow, if he starts feeling like you are on a power trip or he is losing controle he will be come a real pain, some of them just start out on power trips and then you are screwed.

[burninbriar]

, if he starts feeling like you are on a power trip or he is losing controle he will be come a real pain, some of them just start out on power trips and then you are screwed.

LOL Diplomacy is the word for the day.

[bretsk2500]

some of them just start out on power trips and then you are screwed.

ain't that the truth... one of the state inspectors here forced the electricians to completely rewire a ticket booth across the driveway from a building we were putting up at a local HS. the pisser is that the ticket booth had NOTHING to do with our work, no power for it came from our building. the guy was famous for that kind of ****. grrr.

[Bob Kraemer]

ain't that the truth... one of the state inspectors here forced the electricians to completely rewire a ticket booth across the driveway from a building we were putting up at a local HS. the pisser is that the ticket booth had NOTHING to do with our work, no power for it came from our building. the guy was famous for that kind of ****. grrr.

That would be considered an "EXTRA" to the GC

[leeschaumberg]

1 black wire - hot or 120 V
1 white wire - negative which is circuit ground
1 uninsulated or bare wire - building ground

[harcosparky]

" reidentifying " a wire with tape, marker or whatever won't make ot past a code inspector.

Let's not rehash the GND/NEU thing here. In a single phase service both GND and NEUTRAL are the same thing, physically and electrically.

Simply put he wants to use 12/2 and the inspector wants 12/3.

He could use 12/2 but it wouldn't be up to LOCAL code.

Keyword LOCAL as NEC is a guide. Local gov't can demand more.

I would say if you were not being inspected 12/2 would work -IF- the bare gnd conductor is of the same wire gage.

It makes no sense to me ... in my house a 240V Dryer has a 3 wire hookup, in a new house it is 4 wire. The new codes demand a Red / Black / White / Green(bare) wire. When in fact on single phase wiring the Green & Whites are tied together at the power company transformer and your house.

Oddly when you read the NEC code they tell you ... " If you move a 3 wire appliance into a new installation you will have to have a 4 wire power cable installed "

[neophyte]

If the cable is 12/2 w/gnd you are allowed to identify the white conductor with a permanent marker or black tape to be used as phase conductor only if it part of a cable assembly IE: romex, MC cable BX etc!
If the wires are installed in conduit you are not allowed to do this, with the exception being the conductors are over #6 awg.
But as the others stated the inspector has jurisdiction over what the code says.

Thank you Bob. You confirmed what I thought......
I picked up a copy of Wiring Simplified 41st Edition today....which by the way is based on the 2005 NEC. Sure enough on page 51 it states, " white can be used for ungrounded purposes when it is part of a cable assembly brought to a switch or for a 240-volt load, but even here it must be reidentified as other than white at all visible points and at termination."

Also finally talked to the electrician here that installed my 200 amp service. His comment?? "The guys an idiot" ....... hmmm

I also understand what harcosparky is saying about LOCAL code. We are talking Ottumwa IA here not New York City ..... I have read the local code ...all one page of it and it says nothing about the reidentification of conductors. I don't see how using 12-3 instead of 12-2 would be considered an upgrade to the code....especially when that just leaves one conductor sitting in the box. Your correct though.....the inspector non the less does have the final say.

Thank you again Bob for shooting from the hip and talking straight.

[Bob Kraemer]

" reidentifying " a wire with tape, marker or whatever won't make ot past a code inspector.

Let's not rehash the GND/NEU thing here. In a single phase service both GND and NEUTRAL are the same thing, physically and electrically.

Simply put he wants to use 12/2 and the inspector wants 12/3.

He could use 12/2 but it wouldn't be up to LOCAL code.

Keyword LOCAL as NEC is a guide. Local gov't can demand more.

I would say if you were not being inspected 12/2 would work -IF- the bare gnd conductor is of the same wire gage.

It makes no sense to me ... in my house a 240V Dryer has a 3 wire hookup, in a new house it is 4 wire. The new codes demand a Red / Black / White / Green(bare) wire. When in fact on single phase wiring the Green & Whites are tied together at the power company transformer and your house.

Oddly when you read the NEC code they tell you ... " If you move a 3 wire appliance into a new installation you will have to have a 4 wire power cable installed "

Don't mean to disagree with you & no offence intended but the neutral or grounded conductor are not the same thing as a ground wire or equipment ground. They preform 2 different functions. The neutral is a load carrying conductor that is why you have to count all neutrals when sizing conduit or for derating purposes. Yes they are tied together at the main panel & transformer that is why the neutral is also called a grounded conductor
The reason you have to install a 4 wire cord on dryers equipped with a 3 wire cord in a new house is because the neutral is a load carrying conductor. You have to remove the bonding jumper on the center tap lug in the dryer attach the neutral there and install a lug or other attachment means to ground the dryer.
An example of what the neutral wire does is a light bulb. For a light bulb to work you have to have what is called controlled resistance. In essence you are creating a short circuit between the hot & neutral causing the filament to glow, but it is not enough to cause the circuit breaker or fuse to trip.
A ground wire will do the same thing, but since it doesn't have any insulation around the conductor to protect it & other conductors from the heat created, you cannot use the ground wire as a neutral conductor.
The intent of the ground wire is to provided a direct path to ground in case of a short circuit.
I am not an engineer but I hope I helped to clarify the difference.