Wiring Lights in series...

[John Grabowski]

I am looking for some advice on how to wire all my new lights together. I have just purchased 10 new industrial t-8 fixtures for my shop. I was to wire them all together directly to the panel. Is pigtailing all of these together in series the correct way to wire them? Any other suggestions?

Thanks,

John G

[russell lusthaus]

I think that maybe you should wire them in parallel, not series. I am sure some other more knowledgable persons will be along soon.

Or you could do what I did. I surface mounted conduit, installed receptacles on the ceiling, and plugged the fixtures in, all wired to a switch on its own circuit (actually I used two lighting circuits).

[Dave Wagner]

Yes, black to black and white to white, which is PARALLEL. If you put in SERIES, the voltage would drop and you would get no light.
You could switch the banks of so many if you have the switches and wiring.

[John Grabowski]

I suppose I should shed some more light on my idea(pun intended). I have open rafters that are 14 feet up. I dont really want to mount 5 or more outlets up there in order to plug them in. I have Industrial Fixtures with electronic ballasts so I am not really worried about replacing the fixtures.

I just want to make sure that it is ok to run a wire to the light and run one out of the fixture and wire nut them together. Is that ok to do? All my elec. in my garage is running on dedicated 20 amp circuits and the appropirate wiring to handle it.

Thanks for any help.

John G

[Dave Gaul]

John, I am thinking you are using the term "series" in a improper way for the topic. Electrically, you do not wire lights in series, nor outlets/circuits at all. Electrically, they are wired in parrallel. The use of "pigtailing" is to accomplish wiring components such as outlets in parrallel.
What you basically want to do is electrically connect all the white wires to each other, all the black wires to each other and connect all the grounds(greens) together.

Do you have any wiring experience? If not, find someone to help you who knows what they are doing and have them teach you. If you have even just a little bit of experience, searching on google should give you some helpful information and diagrams on how to properly do this.

[Dave Gaul]

Looks like more posts have been written while I was typing!

Sounds like what you want to do is fine, as long as your connections are made inside a box (your wire nut connections). All connections should be inside a connection box, light box, outlet box or inside the lighting fixture itself... basically, you shouldn't be able to look up and see wire nuts!

[Dave Wagner]

You would have to look at the rating of each fixture, (XX amps and/or Watts)

ie.) if each one draws 2 amps, then 2 x 10 is 20 amps, that would be too much for 1 20 amp circuit. Maybe break them down to 2 sections of 5 each lights, depending.

But, yes, you can come off the first fixture (outlet or whatever) and run end to end to each light (just keep the black to black and white to white), you should also have the connections in a box or in the light itself.

[John Grabowski]

Thanks...I think I have it now...I do have some electrical experience...I am wiring them inside of the lighting fixture so no wire nuts will be exposed.

I thank you all for the fast responses...I see that it is a parallel circuit...I have already calculated that my draw is going to be less than 75% for the lighting fixtures that I am using so I am good.

John G

[Stephen Saar]

You can not wire electrical devices in series with each other. Well you could, but you would cause all sorts of weird issues. Each one will have to be wired in parallel.

[Dave Gaul]

Dave W. has a valid concern, but 2 amps is HUGE for a flourescent light. A 2a bulb on a 120V circuit would be 240 watts! (Power=Voltage X Current)
So a T8 bulb is 32 watts, right?
Then 23w/120v = .267 amps.
So if you have 10 T8's, 10 X .267 = 2.67 amps.
Even if you have 10 Double T8's you would have 5.34 amps.
Plenty of room for your lights on a 20amp circuit!

[George Bregar]

I'll add that you need to have a romex clamp for each knockout that a cable runs through to enter the fixture. All but the last will have two cables (in/out) and both can use the same knockout.

[John Grabowski]

One last question...I have all kinds of 12/2 wire...Can I use that or should I buy 14/2?

Thanks again,

John G

[George Bregar]

One last question...I have all kinds of 12/2 wire...Can I use that or should I buy 14/2?

Thanks again,

John G 12 is required on a 20A circuit

[Dave Gaul]

Nothing wrong with the 12/2 wire. 12/2 has more ampacity than 14/2. Only advantage would be that the 14 would be easier to bend, would be cheaper if bought new, but you have the 12 laying around and won't really need it for anything else, just use the 12/2! My entire shop is either 12/2 or 12/3....

[Dave Gaul]

Oh yeah, George is right! Forgot you said you were using a 20a breaker... wiring MUST match the size of the breaker!

[George Bregar]

Yeah, my 8' t8's (4-4' 32w bulbs) draw .95A...he's fine

[Lee Schierer]

You'll use less wire coming from a junction box with just a pig tail to each light, making your connections to the light and on to the next in the junction box. It will also be easier in the future to replace fixtures and or revise how they connect to each other. If you decide to remove a fixture later you will need to add a junction box anyway.

[George Bregar]

You'll use less wire coming from a junction box with just a pig tail to each light, making your connections to the light and on to the next in the junction box. It will also be easier in the future to replace fixtures and or revise how they connect to each other. If you decide to remove a fixture later you will need to add a junction box anyway. Not sure how you figure "less wire"...seems to me you would use more because you are adding the pigtails. You still need to come out of the boxes to wire the pigtails...why not just run that into the fixture and wire it all together? I also don't see how replacing fixtures is easier. True if you were to eliminate a fixture you would have to add a j-box, although I would think that would be unlikely.

[Dave Gaul]

Another thing, if you plan to have all those T8's on the same circuit breaker, I strongly suggest connecting or plugging at least one more light into a seperate circuit. I learned this one the hard way! Had DC running, Shop-Vac and router with all lights on. DC on one circuit, vac, router and lights on the other (only two circuits in my dinky shop!)... and for some reason the circuit w/lights tripped... an wow was it dark in there!!! Now I plug in a floor lamp w/CFL bulbs on the opposite circuit and just keep it in the corner/out of the way for safety.

[Dave Gaul]

I think what Lee was saying is to pigtail at the junction box, not at the light?

[George Bregar]

Another thing, if you plan to have all those T8's on the same circuit breaker, I strongly suggest connecting or plugging at least one more light into a seperate circuit. I learned this one the hard way! Had DC running, Shop-Vac and router with all lights on. DC on one circuit, vac, router and lights on the other (only two circuits in my dinky shop!)... and for some reason the circuit w/lights tripped... an wow was it dark in there!!! Now I plug in a floor lamp w/CFL bulbs on the opposite circuit and just keep it in the corner/out of the way for safety. No, the better solution is to have lights on a dedicated circuit for this very reason.

[George Bregar]

I think what Lee was saying is to pigtail at the junction box, not at the light? No hew was clearly describing having a jbox associated with each fixture and running a pigtail out to it.

[Faust M. Ruggiero]

John,
Think about installing the lights on two separate switches, not because of amperage but for convenience. If you switch them by rows or even every other light or in such a way that two come on with one switch and the balance with another. The life of a fluorescent light is shortened by frequent on-off cycles. Suppose you need to go in the shop to pick up a tool to use elsewhere. Why turn on 10 lights every time.
fmr

[George Bregar]

John,
Think about installing the lights on two separate switches, not because of amperage but for convenience. If you switch them by rows or even every other light or in such a way that two come on with one switch and the balance with another. The life of a fluorescent light is shortened by frequent on-off cycles. Suppose you need to go in the shop to pick up a tool to use elsewhere. Why turn on 10 lights every time.
fmr Also helps to keep costs down. I have three rows of t8's switched seperately. If I'm finishing or just putzing around I can turn on just the lights where I'm at. Ran power to a triple gang, pigtailed to three switches, and then out to each of the three rows

[Lee Schierer]

No hew was clearly describing having a jbox associated with each fixture and running a pigtail out to it.

I was thinking that running the power down to a light and then back up and on to the next light would use twice the wire as a simple pigtail from a box mounted up in the ceiling. Also most lights aren't sturdy enough to handle two sets of #12/2 w ground wiring coming and going.

[George Bregar]

I was thinking that running the power down to a light and then back up and on to the next light would use twice the wire as a simple pigtail from a box mounted up in the ceiling. Also most lights aren't sturdy enough to handle two sets of #12/2 w ground wiring coming and going.OK, that would be true assuming the lights are hanging, in which case I would pigtail one cable down to the fixture also. I guess I'm assuming they are mounted to the rafters. Not sure about the second part...what sturdiness is required for two 12/2 romex cables. :confused: You just run the cables to a knockout/romex clamp.