Power cord ??

[HeloMech]

I'm trying to wire up a couple lights that were hard wired into a vehicle. I cut the wires from the harness and now have a light with 1 red wire, 1 black wire. I have an old two prong cord that I cut off an old heater. Which blade on the plug is positive and negative? Wide blade, skinny blade...

 

[matt151617]

You're trying to wire a car light to household current? You can't do this without a transformer. 12 volts DC vs 120 volts AC...

 

[6768rogues]

I am assuming that you are talking about 120V lights that were mounted on a vehicle. On a 120V plug, the large slot is the white (neutral) side and the small slot is the hot side, whether it is black or red depends on what is going on with the wiring.

 

[wyliesdiesels]

I'm trying to wire up a couple lights that were hard wired into a vehicle. I cut the wires from the harness and now have a light with 1 red wire, 1 black wire. I have an old two prong cord that I cut off an old heater. Which blade on the plug is positive and negative? Wide blade, skinny blade...

First off, AC electricity does not have positive and negative. I suggest using automotive primary wire. DC electricity has a higher chance of leaking through insulation! But if u must re-purpose this cord, the wide blade is neutral. If u can't identify which ends are the same, use a multimeter and do a continuity test!

 

[wyliesdiesels]

You're trying to wire a car light to household current? You can't do this without a transformer. 12 volts DC vs 120 volts AC...

I read it as he is trying to wire DC lights to his car with a salvaged AC cord. But I can see it your way too. OP- we need more info here!

 

[sberry]

The wide blade is actually the grounded conductor, not a neutral,,, ha

 

[wyliesdiesels]

Semantics!

 

[HeloMech]

Question has been answered about the plug blades. Bulb has been changed to a 120v bulb. All I'm trying to do its light up a Corvette rear end shell. Thanks for all the "different" replies.

 

[wyliesdiesels]

Ok. And what is your power source for this light? AC or DC car battery?

 

[HeloMech]

AC outlet.

 

[wyliesdiesels]

Ok so If u mix up neutral and hot in ac electricity, the device will still work but its not a good idea. Since, ur using a dc fixture, I would wire the red to hot and the black to neutral!

 

[ddawg16]

As a side note.....when it comes to bulbs....there is not positive or negative....

 

[6768rogues]

If the fixture is not rated for 120V AC, don't use it on that current. If I am understanding correctly, you are using a 12V device with the bulb swapped out to a 120V unit.

 

[wyliesdiesels]

Good point but I doubt it will be an issue unless he put in a high wattage bulb! What size bulb did u use OP?

 

[rodm1]

Question has been answered about the plug blades. Bulb has been changed to a 120v bulb. All I'm trying to do its light up a Corvette rear end shell. Thanks for all the "different" replies.

Why not go with 12v LED's?

 

[Socophreak]

Or OP could use a small transformer to step 120V down to 12V. Incandescent car lights do not care AC or DC.

An old PC power supply or laptop supply would also do the trick.

 

[sberry]

Another vote for not using a 12V fixture for this.

 

[acer66]

As a side note.....when it comes to bulbs....there is not positive or negative....

But on an even further away side note
.... at least if it`s 120V there is a right and a wrong way to wire the socket for the bulb....

 

[sberry]

Semantics!

I just figured I would toss that in there since we bicker about the fine points of code here anyway it really is more than semantics, its fundamental, it isn't a neutral wire. The code book doesn't call it a neutral. They are quite explicit about it. They don't even use the term neutral in service, art 230

As for the base of the fixture it should be connected to the grounded conductor.

While we are on semantics where is the word subpanel in the code book?

 

[wyliesdiesels]

I just figured I would toss that in there since we bicker about the fine points of code here anyway it really is more than semantics, its fundamental, it isn't a neutral wire. The code book doesn't call it a neutral. They are quite explicit about it. They don't even use the term neutral in service, art 230

As for the base of the fixture it should be connected to the grounded conductor.

While we are on semantics where is the word subpanel in the code book?

Really? Ever read NEC Art. 200.4?

Unless permitted elsewhere in the NEC, neutral conductors are not to be used for more than one branch circuit or for more than one multiwire branch circuit. Neutral conductors also are not to be used for more than one set of ungrounded feeder conductors.

 

[rodm1]

Ok here is a PDF of a 12v LED lights that will work. I have several of these lights and they are very bright and will work.

www.home-machine-shop.com/Light_Up.../LightUpYourMill_2.pdf

 

[sberry]

If you are trying to use it for more than one circuit you would be tring to make a neutral out of a wire its not, in a multi wire it is a neutral which describes its operation. Like in 200.2, general it describes it as a grounded neutral system not a grounded neutral wire.
I figure you are sharper than I am but where the heck is 200.4, I am looking square at a 2002 code book goes from 200.3 to 200.6. ??? One of us has something wrong, I assume you copied this? I am going to assume I am wrong, I can see from opening the book on occasion the last couple days I would have to study.

 

[sberry]

I was ********* ahead. reading 210.4 got to go back to basic, wtf in terms I can understand is happening with A B and C, exception 2 Fr my purpose is a 2 wire 240 circuit, ok? , is B describing maybe a range and stovetop each wired to same circuit? ,,

Ok,, I think I get itIt can only serve this load, in other words no circuits with 120 outlets and 240 outlets? Iam reading this again, B means a double pole breaker on multi wire outlets, exception 2 must permit it places other thaqn dwelling? Going to take ma a day to digest this one thought, ha

Wasnt some of this involved in a code change, the stuff with the same yoke.

 

[sberry]

but on an even further away side note
.... At least if it`s 120v there is a right and a wrong way to wire the socket for the bulb....

200.11

 

[sberry]

But on an even further away side note
.... at least if it`s 120V there is a right and a wrong way to wire the socket for the bulb....

200.11 I believe that to be correct.

 

[mrb]

ugh. if its an automotive socket, the shell is 'ground' and is common to whatever the socket is mounted to. wiring 120v ac like this is very dangerous.

 

[wyliesdiesels]

If you are trying to use it for more than one circuit you would be trying to make a neutral out of a wire its not, in a multi wire it is a neutral which describes its operation. Like in 200.2, in general it describes it as a grounded neutral system not a grounded neutral wire.
I figure you are sharper than I am but where the heck is 200.4, I am looking square at a 2002 code book goes from 200.3 to 200.6. ??? One of us has something wrong, I assume you copied this? I am going to assume I am wrong, I can see from opening the book on occasion the last couple days I would have to study.

Yes, I copied it from my 2011 Ugly's Book. I can't find my NEC book so I verified it online! I think it was added in 2008 so that's why you're not finding it!

In regards to understanding it, I think you're reading it wrong and reading into it too much. I take it to mean that neutral conductors should not be used for more than one circuit so that it doesn't become overloaded. It says nothing about changing the definition of a wire based on how u use it or as u said making a wire a neutral when its not. And I called my friend who's a C-10 and he agrees- its there because some people may think a neutral can be used for more than one circuit since its common to both legs and thus overload it!