Help please - How many light fixtures on one outlet

[littlebritishcar]

So I read Dr. Johnny Fever's fluorescent light review and decided on these but I am wondering how many fixtures I can plug into one outlet if I plug them into one of those outlet strip surge things? It says it is energy efficient so maybe it doesn't use too much electricity. Do you think four or six on each outlet would be too much? Somebody told me that my outlet is a 15 but I don't know anything about electrics. Thanks for all the help.

http://www.homedepot.com/p/Lithonia-Lighting-All-Season-Shop-Light-4-ft-2-Light-Grey-T8-Strip-Fluorescent-1242ZG-RE/202052422#specifications

 

[pattenp]

The circuit size its what determines the number of fixtures you can have. Lights are considered a continuous load so the total continuous amps should not exceed 80% of the circuit capacity. I believe those fixtures use about a half amp each. As an example if the circuit is 15A then you could use 20 or so of those fixtures on the circuit if the circuit doesn't supply power for any other uses.

 

[Charles (in GA)]

Even if it is a 20 amp circuit, the OP is using a outlet strip which is going to be limited to 15 amps max, and the receptacle on the 20 amp circuit is almost for certain, a 15 amp rated receptacle which (if a duplex receptacle or more than one) is quite legal......... which still puts us at way more than the OP would ever be able to plug into one strip....... more strips plugged into the first one? and extension cords........ fireman's nightmare.

OP really needs to consider doing this permanently, and properly.

Charles

 

[Stuart in MN]

The outlet strip should have a label on it, most will say 15 amps but I believe I've seen some that were limited to 12 amps or less.

 

[pattenp]

Definitely don't daisy chain power strips to get enough plug spaces to hook up multiple lights. Only use one power strip per wall/ceiling outlet. Technically you can fill up the power strip, but the total continuous amp load on the circuit or the power strip should not exceed 80% amp capacity as I said earlier. The best answer is what Charles said, do it properly. That means not using a bunch of power strips and or extension cords.

 

[DenisG]

The basic electrical equation is: Watts = amps x volts (ignoring power factor). Sum up the total wattage by adding the wattage of each bulb and then divide the sum by 120 volts. That should give you the total amperage. Don't exceed the design amperage of the circuit.

 

[Kevin C]

The basic electrical equation is: Watts = amps x volts (ignoring power factor). Sum up the total wattage by adding the wattage of each bulb and then divide the sum by 120 volts. That should give you the total amperage. Don't exceed the design amperage of the circuit.

One concern is the power factor on consumer florescent lights is pretty bad. I would try and use the rating on the fixtures label. Or de-rate the calculated current draw by .7 or so.

 

[DenisG]

One concern is the power factor on consumer florescent lights is pretty bad. I would try and use the rating on the fixtures label. Or de-rate the calculated current draw by .7 or so.

You're right (I wasn't sure if electronic ballasts made things better). I should have said for "incandescent lights", but I figured I'd keep it simple.

 

[bczygan]

So I read Dr. Johnny Fever's fluorescent light review and decided on these but I am wondering how many fixtures I can plug into one outlet if I plug them into one of those outlet strip surge things? It says it is energy efficient so maybe it doesn't use too much electricity. Do you think four or six on each outlet would be too much? Somebody told me that my outlet is a 15 but I don't know anything about electrics. Thanks for all the help.

http://www.homedepot.com/p/Lithonia-Lighting-All-Season-Shop-Light-4-ft-2-Light-Grey-T8-Strip-Fluorescent-1242ZG-RE/202052422#specifications

First, understand, that no matter how many of these you have:

Or these:

What matters, is what you have connected to a circuit. And what the circuit is designed to support.

Circuits are protected by fuses or breakers, so if you overload them, the fuse blows or breaker pops.

But just because they are protected, doesn't mean you want to overload them or even come close to it.

First step is to determine the size of the circuit. Check the existing outlets, wiring and breaker or fuse. The wiring is the thing that will ultimately govern, but all items on the circuit need to match, or not exceed the ability of the circuit.

Second step is to find out what is on the circuit that you intend to use. Many circuits in houses will have lighting and power items on the same circuit. There are fixed loads, that are wired in, and potential loads, like lamps or tools that could be plugged into a convenience outlet. And that word convenience is important. Convenience outlets are placed in a residence, by code, so that they are convenient to anything that might need to be connected to them. Having long extension cords or lamp cords running all over a room is dangerous and having these placed in convenient locations minimizes this. Just because you have a half dozen outlets on a circuit, doesn't mean you can plug a hair dryer into every one of them, without overloading the circuit. But in your planning, you need to figure out what loads MIGHT be connected to these outlets.

Once you have determined what capacity your existing circuits have, then you can decide if you can add to an existing circuit, or must add a new one.

Bill

 

[littlebritishcar]

Thanks guys, I appreciate all the help and apologize for being so ignorant. I bought a home electrical book today that was published by Home Depot. While I was there I saw some four-bulb T5 high output fixtures and man, they are BRIGHT! But they are also kind of expensive. I can buy five fixtures and bulbs for the cost of one of these with bulbs. Of course one of the HO units probably puts out the same light as five cheap units Oh well, a lot to think about.

 

[pattenp]

Hey, no apologies needed. We are all ignorant about something.

 

[bczygan]

Thanks guys, I appreciate all the help and apologize for being so ignorant. I bought a home electrical book today that was published by Home Depot. While I was there I saw some four-bulb T5 high output fixtures and man, they are BRIGHT! But they are also kind of expensive. I can buy five fixtures and bulbs for the cost of one of these with bulbs. Of course one of the HO units probably puts out the same light as five cheap units Oh well, a lot to think about.

T8 with daylight bulbs is most cost efficient.