OK-I'm going to walk thru cable routing kinda quick.
This is all pretty straightforward. We'll start with the cord that's going to run from your ballast to your lamp.
Remember, this wiring is on the
HIGH VOLTAGE side of the ballast transformer. HID bulbs operate at a nominal 600 volts AC ( which, as trivia buffs may be aware, was proven by no less than Thomas Edison to be capable of causing a watermelon to explode, properly applied. Thomas Edison must have really loved his job.). There's a very signifigant start-up surge when the bulb fires-
Peak voltage is determined by the bulb's cold resistance factor, but it will be notably higher.
(
Please Please Please don't try to add length to your lamp cord by splicing in romex or an extension cord. They're not designed for this kind of voltage, and very likely to fail. You can buy the right stuff @ Home Depot, if you have to splice in. Or better yet, just buy a longer lampcord and socket set @ your local hydro shop, if you're not very very comfortable with appliance level wiring. F#$king up is a good way to start a fire or fry a ballast, though it does make for interesting fireworks).
So, from the above, we can assume that we want this cable run very neatly, with nothing pulling on it, up off the floor- so we can't step on it, and it will not get wet. It's a very good practice to make sure that you can't touch the lamp cord and any exposed metal plumbing ( pipes, radiators, etc) at the same time.
So, let's start by lowering your reflector down as low as you can ever imagine running it. Now lower it another six inches. Toss a ceiling hook in up by the existing hook that holds the chain running to the socket end of your reflector, and loosely loop the lampcord over this new hook. I generally put on a cable tie, very loosely, so that I can still slide the cord easily, but I know that it's not going to pop off.
Have you thought yet about where your ballast is going to live? Ideally, a the ballast does throw some heat, we'd like to have it out of the room entirely- but this might be overly complicated. If you've sized your ventilation properly, it'll handle the ballast heat just fine.
I've only got one hard and fast rule about ballast placement- IT MUST BE HIGHER THAN MY WAIST.
Why? Because five gallon buckets full of water are heavy, that's why.
Simple fact of the matter is that you will, at some point, be carrying a full five of something in this room. On account of being a primate and all, the easiest way to carry a full, heavy five is by the handle, which puts it down by your knees and out away from your body. If you're short on room, though, or if you need to pour from said five, you're going to rest the base of that five on your hip bone- and that's when you're going to drop it.
Growrooms by their nature pose a high risk of accidental intersections of electricity and water. There's a reason why building codes require a UL listing for water heaters and washing machines- and these are the only things that I can think of in the average home that bring water and electricity into the same proximity as a growroom. ( OK, hot tubs and fridges w/ icemakers... I'll be over around eight, have margaritas ready...).
I was once standing next to a 1KW halide ballast that got suddenly, catastrophically wet. About 8 milliseconds later, I was sitting a good ways away- then running for a fire extinguisher.
Seriously, keep your ballast up out of the spill zone- water and high voltage transformer plates do not play well together!!
So figure out where you're going to put the ballast, and string the lamp cord over to where it's going. I just use ceiling hooks, myself. Run the cord as straight as possible across the ceiling and then down the wall to your ballast. Ballast sitting on a shelf is fine, but I like to actually hang them right on the wall. Quality ballasts will have some kind of rigging hardware built in- keyhole slots in the handle, or a bracket on the bottom of the ballast. ( You may have to pop the rubber feet out.) I usually don't bother trying to acoustically decouple the ballast from the wall, but if the buzz makes ya nuts, slip a couple of neoprene washers between the wall and the ballast when you hang it.
Anyway, ballast on a shelf is fine- if you can spare the shelf space. I'd be really surprised if you can't find anything better to do with that shelf, though. Ballast on the floor, though... not a risk that, to me, is worth the benefits. ( Hint- there are no real benefits. You're just struggling with inertia).
Same thing with extension cords and suchlike- up off the floor, and ideally mounted on the ceiling. I in fact have, more than once, had an extension ground out through a puddle and then through me. The sensation is really indescribable, and you really don't want to find out.
Plug the lamp cord into the ballast, and gather any excess at that end into manageable loops. Use a cable tie to secure these loops to your last ceiling hook. DO NOT plug the ballast into power quite yet.
Now raise the reflector up to the highest level that you will ever ever use it, and figure out what you're going to do with the excess cable at this end. I like a bicycle hook that I can throw loops over as they develop. Make it easy on yourself- make it easy to keep things neat.
Go ahead and put your bulb into the socket, remembering to wipe it down when you're done. The oils from your hands can cause hot spots on the surface of the bulb, which could cause ( rapid, spectacular) failure. I just use a clean paper towel.
Ok, take a break, blow a bowl, and get some sunglasses.
Ready? High? Feeling sassy?
Go ahead and plug that sucker in. You deserve it. ( Now you know why you wanted sunglasses.)
I don't know about anybody else, but the sound of a ballast getting powered just makes me feel like a little kid. Seriously, all warm and fuzzy inside...
OK, next thing to do is cable in the fan, but I think that we should go over environmental controllers before we do that. There may be decisions to be made about where to plug things in, and it's helpful to know why. There are also some things to know about how the controllers work, and what they need to work well.
Now that I know that people are actually looking at this, and I'm not just typing into the wind, installments will come much more quickly.