moonlight power supply question

[jdizzle3id]

So I have everything I need to put together my moonlights but I don't have a multimeter at the moment. All I need to know is, which wire is positive and which is negative on the power supply. One of the wires is solid black and the other is black with a white stripe. Is there a standard for this type of thing or no? I will have access to multi-meter in about a week and a half so, if need be, I can just wait until then. Otherwise if someone could tell me which wire is positive I would greatly appreciate it.

[Ziggy953]

I've always thought that the black with white on it was positive and the black was neg....I could be wrong about that though.....

[gadgetguy]

Yep, that's correct.

[jdizzle3id]

That's what I thought too. I'll just wire one with a resistor like that and see if it lights up. Worst case senario, I'm out one led.

[leoslizards]

Don't forget to post your results with pics as soon as your done.

[SparKy697]

Blk/Wht = +
Blk = -

That has been my experience also. As you said, you can test with a LED. Chances are that you will not ruin the LED, it seems that most of them have PIV rating high enough to handle it, remember that while they emit light they are still just a diode and have to be able to handle some reverse voltage. Just bump the wires together and see if you get light.

[tropicalfish]

Sparky, does that mean I need to rewire my hoods? I used to think that black was the hot wire and I wired it to the switch. Do I need to flip it around?

[SparKy697]

If they are working I would say no. The best bet is to check it with a meter though. If you have an LED wired backward, they will just not light. I'd say that you are probably ok

[tropicalfish]

Well, my hoods were DIY Compact fluorescent screw-in lights, not LEDs

[jdizzle3id]

Well I finally got a chance to try it. Striped was positve. Thanks all for the input. I haven't hooked up the whole system yet. I'll probably get working on that tonight.

[SparKy697]

Originally Posted by tropicalfish

Well, my hoods were DIY Compact fluorescent screw-in lights, not LEDs

Oh whole different question. If you are speaking of a 110v system, you are correct! The white wire is the neutral and the colored wire, in this case, is the hot. You are also correct in switching the hot lead. Never, never, never switch the neutral.

[tropicalfish]

*phew*.

So Black is hot, white is neutral,.. right?
Then I can not worry so much anymore hahaha

[Ziggy953]

I just want to make a quick statement here...I don't want to get anyone upset or anything like that but I have read posts where people have misread or miswired things and have ended up shorting things out or even worse causing fires. Please if you aren't sure of what you are doing ask a professional before you put power to something that you have wired! Your life and your home is not worth saving a few bucks. If nothing else invest a little bit of money in a couple of DIY books on wiring from HD or Lowes!

[tropicalfish]

heh, my wiring has gone on for several weeks without any messups,... I just got scared for a second

[Ziggy953]

Like I said...I wasn't trying to pinpoint anyone...just making a general statement.

[SparKy697]

I can think of no way of saying this that wont sound sarcastic. so I will just say it. I am an expert on this subject. It's what I do for a living. I have over 15 years experience and training.

I do agree with you especially when we are talking about ac voltages like those you are exposed to with normal household wiring. The relatively low voltages like what we are talking about with LED lighting are of little concern as far as safety or fire hazard. The biggest danger is possibly damaging the LEDs. If any think I would like to suggest that you (everybody) are as specific and detailed as you can be when you ask your questions about electricity.

[Ziggy953]

I wasn't talking about this situation in particular. I think you made my point though. If you don't know for sure what you are doing with electricity then consult a pro. That is all I was trying to get across.

[SparKy697]

Point taken.

Can't stress that enough.

[Alshain]

Yeah, I work in electronics as well. Specifically, 12 volt natural gas wellhead monitoring devices. I can't tell you how many times I "hot wire" those controllers in my test lab, voltage from most common DC transformers will likely not cause any damage but you should be carefull none the less. I did start a fire once by plugging 12v into a 4-20mA connector by mistake, but thats another story.