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Metal halide wiring

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I finally built the light box for the new lowland chamber. I've assembled the spiderlight reflector (that was irritating getting the spacers between the reflector and box lid) and 4" fan for the light box. But now I've hit an impass when I go to hook the balast up to the mogul socket. From the Hamilton balast I have a heavy duty cord with three wires Green, Black & White, my mogul socket only has Black & White. Where does the green wire go?

I purchased several MH balasts and reflectors second hand from a guy who was upgrading his 225G reef lighting so I don't have any wiring instructions. Also it was over a year ago when I got them I no longer have his # to call and ask him so if any of you have experience with MH I'd be very grateful for any advice!

Thanks folks!  
All I can tell you is that the green wire is the ground. I have no clue where it should go though
You need to connect the green wire to a part of the frame of your lights. I think that there should be a screw on the frame for that purpose. If there isn't any, you might want to make a hole just for that. I'm not an electrician or anything, but I've had to put up/take down something like 10 lights around my house recently, and there's always a screw to connect the ground wire.

Hey Sword, like mindmaze said you can hook the green wire to the frame of the light black-power, white-nutreal, green-ground. green does not have to be hooked up to have the light work. it is a safty wire to direct the current.

if you are wanting to know how to hook it up to a outlet. white to white, black to black, green to the the screw off to the side of the plug.

hope that helps you with it.
I'm new with Neps, but am a licensed contractor. The colors are American. I wish you could post a picture. Where you actually plug in the cord to your house outlet, is it a three pronged plug, or two?

PM me if you want.
I would also like to add that to be safe you should plug your lamp in to a GFI outlet, this way you minimize the risk of fire.

Fire and shock.

Being realistic, you could just cut of the green wire and chances are that it would work fine. There is a very small chance that thing could go wrong though.

I would just cut off the green wire, but there is potential danger. Here in America with our 110 stuff, people can get away with more shortcuts.
Oh here's a picture of what I'm connecting:

On the right are the two wires which come from the Mogul socket (that the MH bulb screws into) on the left are the three wires which come out of the balast and are to be (have been before I purchased them) connected to the socket. I just don't know what to do with that extra green wire. If it is just a ground wire or neutral or whatever can I just put a screw into the light box and attach the green wire to that?

The outlet that plugs into my wall is a normal 3 prong grounded plug (the same type of plug that's on my  PC and aquarium power strips) no problems or modifications with that my condo is equipped for grounded plugs.
Sword, black to black, white to white, cap off the green with a wire nut and your set.
  • #10
Speaking practically, I think George is right. You start with a ground, then go without one, then go to a ground.

The white is neutral, green is ground. If it will make you feel better, attach the green to anything ferrous with a screw.
  • #11
well with looking at the set up now from the picture. that is what i would do. heck i really dought he is going to be inspected. i'm not a licensed contractor but, i did go to school for a one year for a/c & heating and besides that my dad is a building inspector and has his G.C. not bragging thu
  • #12
I think your asking for trouble, have you ever seen a manufacturer ever leave a ground loose?
No, why, because its unsafe!
Just anchor the screw on the box that youve mounted the mogul socket to assuming you havent mounted the mogul socket to the wood.

  • #13
no i havn't seen a manufacture leave a ground loose but, i have seen them capped off with a wire nut if not needed in a house hold but, if ya want to be safe since you are have humidity in the air at all time i would electical tape everything so it is water proof.
  • #14
Hi Josh,

the green wire is for grounding the reflector of your metal halide lamp, which is most propably made out of metal (i.e. aluminum). MH lamps do need a voltage of 4-5kV to start lighting and especially in a humid environment it is an extremely high risk not to ground all surrounding conductive metals!

Be cautious!

  • #15
From a professional EE point of view, cut yourself a lenght of wire to use to connect the green wire to the metal reflector. Just in case the bulb explodes from water contact. 120 wont hurt you but it will start a fire.

Another point of view, the green wire is connected to the 3rd prong on a plug that everyone cuts off so that the plug will fit in one of those cheap extension chords. My lighting currently is ungrounded and the only problem with it is the mild shock I get if I touch the reflector while I'm barefoot on the concrete basement floor. (you won't have this problem, it's a florescent lighting thing).

  • #16
The bulb will probably never come in contact with any water as it will be seperated from the "growing area" by the terrariums lid glass.

So I should attach the green wire to my reflector (it's made of bent aluminum)? I will not be turning the lights on and off but running them on a grounded timer. Is there any certain Voltage the timer needs to be? The ones I have are rated at 1825 Watts but no mention of Voltage. I could add I do automate my Highland tank's air conditioner on one of these grounded timers in the summer and have had no problems but I don't know if that's the same as a high output bulb....
  • #17
Is there any certain Voltage the timer needs to be?

Where does the timer go? If before the ballast, and the ballast is 120, then the timer will also need to be the same. Most timers you buy are 24 volts, so in that case, it wont work.
  • #18
If you are referring to the cheap rotary timers that you can buy at walmart to plug lights into then that is fine. Most anything you plug into the wall and has a plug recepticle for your light will work.

As tim mentioned if it is a specialized timer that you have to wire it may not be compatible.

keep it simple

and yes, place the green wire right on the aluminum housing using a small screw or grounding lug.
  • #19
No, it's not a special timer, just an Ingraham "heavy duty"dial timer. It's just got a 3 prong outlet/inlet (as is needed for the MH powercord). I also have one by GE that accepts grounded 3 prong cords. Here's the details on the back of the Ingraham (which I ran my AC with last summer):

CAPACITY: 15 Amps; 120 VAC; 60 Hz; 1875 Watts, 1/3 HP Motor; 15 Amps Tungsten

The GE one is probably the same.

Do you think this will be OK?
  • #20
Amps is what you need to be concerned with regarding the timer. The ballast will pull alot of amps especially when it is firing the light up. There should be a rating somewhere on the ballast listing how many amps it draws during lighting the bulb and normal running (operating line amps @120v). The timer rating needs to be equal to this or higher. Otherwise you risk burning up the timer and a fire.

Most likely the 15 amp rating on the timer is fine for a single metal halide ballast. A quick look at the specs on some metal halide ballasts shows 400watt units using about 3.5-4 operating line amps.
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