Identifying wires

[Emaline]

Hi, I've got a bunch of old lighting fixtures with different wire colors than I'm used to. There are two white, and one white with green stripe. How do I tell which is neutral and which is hot? (Sorry if this is a stupidly basic question. I'm new to this)

 

[gafftaper]

My guess is that the green stripe is a ground and the two white wires don't matter which is hot and which is neutral. But you should never trust the colors on older equipment without doing some investigation... it's not worth risking your life over. When it comes to you straight from ETC, you can assume things are wired correct, but when it's been around for years... how do you know what has been done to it since it was manufactured. Does it have a connector on it or are you trying to install a connector? What type of connector? What type of light fixture is it? What type of lamp? Can you open it up and see where the wires connect on the inside? If you don't know model names take a few pictures and post them and we should be able to help you.

 

[TimMc]

What kind of fixture is this? Brand/model/approx age?

You can use an Ohm meter to find where the wires terminate inside the fixture.

 

[gafftaper]

By the way, don't worry about posting basic questions we hang out here because we want to help you learn and keep you safe! Sometimes the basic questions are the most critical to keeping you safe.

 

[Emaline]

My guess is that the green stripe is a ground and the two white wires don't matter which is hot and which is neutral. But you should never trust the colors on older equipment without doing some investigation... it's not worth risking your life over. When it comes to you straight from ETC, you can assume things are wired correct, but when it's been around for years... how do you know what has been done to it since it was manufactured. Does it have a connector on it or are you trying to install a connector? What type of connector? What type of light fixture is it? What type of lamp? Can you open it up and see where the wires connect on the inside? If you don't know model names take a few pictures and post them and we should be able to help you.

Here's what I'm working with. I've idea how old it is. I inherited a shop with a bunch of these sitting around, so I'm trying to put connectors on so I can see what's going on with them.

 

[almorton]

Sure looks like @gafftaper was on the money. A photo from underneath the lampholder would confirm.

 

[Emaline]

Is this what

Sure looks like @gafftaper was on the money. A photo from underneath the lampholder would confirm.

Is this what you're looking for?

 

[MRW Lights]

If an Altman 6x16 is old than I'm... well let's not go there. From your pictures you can identify the ground and the two leads. @gafftaper gets the answer once again.

And another thing! back in my day... we built Colortran lens tubes by show... in the dark! in the snow! on a hill!

 

[DrewE]

To expand slightly, the reason why it doesn't matter which white wire is hot and which is neutral is because this is a bipin socket, and the two contacts in it are equivalent to each other. With a socket for a screw-base bulb (or a bayonet base, or most anything similar where there's a sleeve around the outside and a nub of some sort on the bottom), the outer shell should be connected to neutral and the inner nub to hot. This is because the shell is much more likely to be accidentally contacted than the inner nub, and so should not be electrically hot. Neutral is, of course, nominally at ground potential.

 

[derekleffew]

Here's what I'm working with. I've [no] idea how old it is.

The Altman 360Q fixture line had a very long life, from 1974-2015. Based on the paint on yours, I'd say it's closer to the former than the latter. Still a serviceable fixture. As has been said, since the unit uses a medium bi-pin lamp, the hot and neutral wires can be interchanged with no ill effects.

You might also want to check out https://www.controlbooth.com/threads/lighting-fixture-maintenance.12561/#post-129613 .

 

[Emaline]

Thanks so much everyone. You were all really helpful

 

[gafftaper]

Thanks so much everyone. You were all really helpful

We are happy to help @Emaline . Be sure to stick around, ask questions, and read a bit every day. There's an entire masters degree of information waiting for you here and a bunch of us are out of work and bored right now, so there are lots of people eager to help! You'll be an expert in no time!

 

[brucek]

Just a heads up - the socket -BPS-1200 tp220 (same as tp-20 but with fins) is now very hard to find! Altman has no stock. Osram / ge / sylvania have removed them from their catalogue.
I used to pay around 12 dollars/each with 36" leads. About two weeks ago I could only find them on amazon for 90 dollars/each.

 

[BillESC]

BruceK,

I have several of the tp-20 sockets in stock.

 

[brucek]

tp-220. the one with fins. tp-22 are the normal ones with no fins. tp-20?

 

[BillESC]

5 with fins, 2 without

 

[brucek]

well, my need is past.....but you may have the last few tp220's to be found...which still suprises me because it was such a heavily used socket. Darn LEDs are ruining everything....

 

[gafftaper]

5 with fins, 2 without

Sounds like you need to put them up on Ebay Bill... maybe you can retire off them.

 

[Jay Ashworth]

The red wire! Cut the *RED* wire!!

 

[Les]

Just did a quick Google search and it looks like TP-22 (finless) are still cheap and easy to find. The TP-220(XL?) with fins was, unfortunately, discontinued several years ago. A darn shame, too.