I need an electrician's brain for a moment.

Brandon and I are wiring the flourescent lights in the paint booth. At first we thought they needed to be wired in series, but quickly found out that was wrong. My research on the web has confused me into thinking that there is some way that I can use 220 VAC to power the lights in series. Is there some nugget of truth here?

If I can't wire them in series, what's the best way to wire them in parallel? As it sits now, I have a power feed line going to a wiring box and 8 3-wire conduits going to the 8 lights. If I have to run them in parallel, obviously I can't just wire nut them all together. It's 12 AWG wire to the lights and the feed needs to be ??/10/8/?? AWG. I've seen the breaker box grounding blocks, and those would be great for connecting all the power lines, but I'm sure the building inspector wouldn't like that much and I'd be really nervous about doing something so hokey.

Obviously, I need help.

If you wire them to 220 they might glow very brightly for a few seconds and then you will have to replace the ballists.

This a new booth? Four banks of lights per side? Any on the ceiling?

Use seperate switches for each bank. You don't need all the lights on except when your painting.

Here you can run up to 15 circuts (lights or plugs) with 14/2

See if there is a electrical code book available for your area.

We would like to have one or two switches max.

The booth has four light about waist high, eight lights at the roofline and four lights in the roof panls.

I can get 20 amp switches, but how many F-lights can be run inside of 20 amps? I guess that's the key bit I'm missing.

A 220V circuit is essentially two 110V hots, a neutral, and a ground (although the ground might not necessarily be in the cable if it's a 3-wire cable). So theoretically you could wire the black wire from each ballast to one of the 220V hot wires (110V each), and the white wires from each ballast tied together with the neutral, and run a separate ground wire from each light to the utility box, as long as the box is itself grounded. You would of course need to drop the circuit breaker size down to 15A to ensure it trips if something every went afoul in the lights.

That said, how hard would it be to just install a 110V 15A breaker in the load-center (breaker box) and run new 14-2 w/ground to the lights in parallel (not series)?

Are you sure you want to wire the stuff yourself, at all, if you're not sure whether it needs to be wired in series or in parallel ?

p.s. Can't think of anything in a house that is wired in series.

Remember the old christmas tree lights that were wired in series? One bulb dies and they all go out. Not a good idea.
David

Do your floros have 220-240v ballasts or are they 110v? Floros come in many flavors! There are 110v, 220v, 208v, 480v etc available. Most common is of course 110v. If they are surplus, make sure you read the ballast!!!!!!!!

Figure about .3 amps (300mA) per lamp (floros) at 110v. You should really only load up a 15amp circuit with 10-12 amps. A 20amp circuit can go up to 17-18amps.

About the only thing in your house wired in series are your Christmas lights.

For your application, 2 switches is better. Have each switch control 8 lights (8 waist high on one switch, 8 overhead on the other). If I was you, I would run a "home run" from the panel to the first switch in #12 (so you can keep your 20amp breaker) then from switch#1 to switch#2. Now run your "switch leg" up from the switches in #14 to a junction box. You simply run a black and white from each light to the J-box. Now tie all blacks together and all whites together.

For a ground, just put a crimp on ring connector on a green wire and put the ring under a self tapping screw driven into the "chassis" of the fixture(make sure not to nick any wires!). Now run green back to your j-box. Do the same thing here(if using metal to ground box) with ring connectors. Run a green back to the panel ground block for each j-box. Dont forget to put a cover on your j-box.

Now you are done! Any questions?

Corby (your friendly neighborhood electrician)

McMark,

Don't be McSpark!

The " Electric Chicken " is not a dance you would probably want to learn!

Balthazar's advice is probably the closest, begin by reading the specs on the ballasts.

As an aside, paint booths ( the inside, not the outside were the "lights" SHOULD be located) are considered "explosive environments" and require special materials (explosion proof junction boxes, for example) in order to avoid flash fires of the aerosol (paint) you will be spraying.

The "flash fire dance" makes the "electric chicken dance" look like a joke.

I would guess you may know an electrician who could use some car work in trade for electrical work, if so that is probably your "best value" for your time and safety.

If you were in Phoenix, and you were interested, I'd do it for you in a minute (well probably a few hours, really).

Be careful,

John

QUOTE (Flat VW @ Feb 17 2005, 08:06 AM)

McMark, Don't be McSpark! The " Electric Chicken " is not a dance you would probably want to learn! Balthazar's advice is probably the closest, begin by reading the specs on the ballasts. As an aside, paint booths ( the inside, not the outside were the "lights" SHOULD be located) are considered "explosive environments" and require special materials (explosion proof junction boxes, for example) in order to avoid flash fires of the aerosol (paint) you will be spraying. The "flash fire dance" makes the "electric chicken dance" look like a joke. I would guess you may know an electrician who could use some car work in trade for electrical work, if so that is probably your "best value" for your time and safety. If you were in Phoenix, and you were interested, I'd do it for you in a minute (well probably a few hours, really). Be careful, John

Sounds like you got lots of experience there.
I get to do the electric chiken dance everyonce in awile just to keep in practice. I bought on of them AC voltage tester pens. Saved my dumb ass more than once. You know when your helper said Ya man I turned it off.

Here is a diagram I made to help explain a bit.

QUOTE (Flat VW @ Feb 17 2005, 09:06 AM)

As an aside, paint booths ( the inside, not the outside were the "lights" SHOULD be located) are considered "explosive environments" and require special materials (explosion proof junction boxes, for example) in order to avoid flash fires of the aerosol (paint) you will be spraying.

The choice of paint and amount of ventilation are big factors. If you're spraying a lot of lacquer with no ventilation, and you love working in a fog of overspray then you better have an explosion-proof lighting system and you better control static electricity too. (it's amazing the high voltages that can build up spraying parts that are not grounded, like small parts hanging on a rack). But the modern 2-part paints (urethanes) do not have the explosive potential as the old solvent-based paints. But you still need adequate ventilation because it's not good having a lot of overspray in the room, not just for safety but to have a quality paint job. The item most likely to cause a fire in a paint booth is the ventilation fan, as if not kept clean and changing the filters it builds up overspray which can catch on fire. My point here is you can use regular fixtures (lights, conduit, switches, etc.) with two-component paints and reasonable ventilation. You will still get overspray collected on lights which you may want to have some kind of protective covers or at least clean them frequently.

Keep in mind that you can wire them in parallel without having a spearate wire going to each light. Most fluorescent lights made for surface installation will have conduit knock-outs on both ends. Run wires into the first one, and connect it to the ballast. Then run another wire from that ballast out the other end of the light and onto the next one. As long as all the wites go to wites and all the blacks go to blacks, it's still electrically parallel.

115v is just hallf the output of a transfomer. The full output is 230v, and it has a center tap. The center tap is white, and is at ground potential (but you don't use it as a ground in most cases). The other outputs of the transformer are both black. Any black to any white will get you 115v and black to black gets you 230. (The reason they do it this way is because if you are grounded and touch any one wire, the worst shock you'll get is 115v) If you have a 230v circuit and need 115v, add a neutral wire (white) and you'll be able to break it into two 115v circuits (make sure the new wire is hefty enough for both 115v circuits). Make sure you keep them separate though, as the potential between the two black wires will still be 230v. I don't know that much about codes, but I'm guessing at the point you break it into two 115v circuts you'll need to install a pair of 115v breakers.

Happy wiring and at least discuss your plan with someone who knows the codes well before you do anything

Joe,

An induction tester as you described is "better than a sharp stick in the eye" as my father would say, but I have heard of "false readings", and I mean "false negative readings" (indicated de-energized when it ain't), not good.

The safest test is still the old style solenoid tester (Wiggins) that both my father and grandfather used, just because it is old don't make it bad.

I hate getting "poked".

john

914 GT, I agree that a possible catastrophe depends on the "explosive range" of the materials being sprayed, but in my experience the fire marshal will not care about the distinction.

I recently worked on a spray booth for "truck bed liners" where the customer demonstrated to the fire marshal that the material to be sprayed was inert (practically will not burn).

The City could give a damn as once the booth is "inaugurated" who can know what kind of material may be sprayed in the future.

Also, the spray booth had to be plumbed to the fire sprinkler system for the existing building and the supply valve for the fire sprinkler system had to be connected to the existing building fire alarm system so that it may be monitored to assure that the fire sprinklers in the booth are "charged".

One in three failures of a fire sprinkler system to control a fire was because a supply valve was shut, thus "no water".

I hope this is not "bad news" for you McMark as a spray booth is a bit of a "can of worms" in regard to what it "triggers" as requirements in the building codes.

Please remember it is only human lives we are talking about, hopefully not yours.


{John replaces the "soap box" back to it's place in corner under the workbench}

John, completely agree with you. Looking back at Mark's post looks like a commercial business situation and not an occasional home hobby setup. You gotta do whats right for codes and insurance in that situation. I know my wife, who's in the insurance business, is not all that happy with me sometimes painting cars in my shop. If there was a fire due to my activities then we could have some real headaches. But I try to be pretty careful with controlling the environment and not leaving paint waste materials around.

okay we have a friendly neiborhood electrician, and i am the friendly master electricican ( also the holder of the royal tp which if get shocked you might need )

as stated figure 1.5 amps for a 4 tube fixture, or .75 amps for a 2 tube fixture, and for each you can put 8 4 tubes and 16 2 tubes ( 12 is safer ) and you cant legally load a 20 amp circuit over 16 amps.

and in a closed room it is safe to have the lights on 2 different circuits, that way if one trips its not completely dark.


and the above a diagram is fine but it leaves out the wiring in the lights themselves, basicly in each light you will have 3 wires coming in 3 wires going out, and 3 wires from the ballast. the grounds as you know are green/ bare copper and all tie together. then the hots all tie together including the black from the ballast. then the nuetrals tie together in cluding the basllast white. now if the are slim line ballasts ( bulbs have 1 fat pin per end ) they are designed when you pull the tubes to cut out the power and ground to the ballast, if you read the ballast it says "cut out lamp holder" some where. on these the white and black wires are at the socket not at the ballast. although you could cut and splice at the ballast but you would need to cap the other wires at the socket.

and i dont know the building type so i would say you need to run the power in emt or may be even threaded pipe
if you need more help give me a call

410 534 7319

Out here lighting circuits are 15 amp and are run w/ 14 gauge wire. 12 gauge wire is for a 20 amp circuit. If you are in a commercial building all of the wire needs to be in conduit. In a residential building only exposed wiring below 8 feet from the floor has to be in conduit. I would use conduit because it is a cleaner installation. Do yourself a favor and buy a how to wire book at the Home Depot to get some basic information about how to wire a circuit.

or wait till the wcc and i can come by. and in commercial buildings you can not run 14 gauge wires you have to use 12 gauge ( nec code )

Okay, quickly, the booth is in a commercial situation. We have gotten 100% approval from the officials for everything we've done (nothing shady). The wiring is happening OUTSIDE the highly ventilated spray area.

The wiring we've pulled so far is all 12 guage.

So, I need to run them in parallel, 8 boxes per switch. I'll call Scott, if I need anything else.

Thanks everybody!

MarkV,

Conduit is correct.

The smallest circuit breaker in commerical work is a 20A.

The wiring would not ever be Romex (NM cable) although Romex would be acceptable in conduit just not necessary.

The wiring for "normal use" for this type of applicaton would be THHN,THWN or that crappy MC (think flexiable metallic sheathed extension cords without the attachment caps {plug ends}).

John