How many on a circuit?

[dusterdemon]

Just wandering if someone could help me figure out if 5 of these lights would be too much for a 20 amp circuit breaker. The tag is on the top of the light. There are two connectors coming out of the light with 3 wires each, does that mean there are 2 ballasts and does the tag account for both?

 

[pattenp]

Re: How many on a circut?

It's the whole fixture amp draw so you're okay with 5 on a 20A circuit.

Edit: You can put 8 of those fixtures on a 20A circuit. It should have 2 ballast.

*

 

[Zeke]

Re: How many on a circut?

With 8 on a 20A circuit, you should use a rated switch. AFAIK, most common wall switches are rated a 15A. That's too close for comfort in my mind.

 

[pattenp]

Re: How many on a circut?

With 8 on a 20A circuit, you should use a rated switch. AFAIK, most common wall switches are rated a 15A. That's too close for comfort in my mind.

Good point. The load should not exceed the switch amp rating. There are 20A wall switches if one is needed.

 

[Charles (in GA)]

Re: How many on a circut?

Two blacks, two whites, yes that is two ballast in there. That I know of, they don't make a single ballast that will drive 6 tubes.

Don't know if that is your light or someone else's but please do something about that cobbled together wiring with no box. and Romex dangling in the open.

Charles

 

[dusterdemon]

Re: How many on a circut?

Thanks for all the replies. That is my light, but it is just temperary. I wanted to see how bright it was so I could get a better idea how many lights I would need. With 5 lights on the circuit is a standard wall switch ok?
Thanks
Warren

 

[pattenp]

Re: How many on a circut?

A 15A wall switch is fine with only having the 5 fixtures. FYI, the total light load should not exceed 80% or 16A on the 20A circuit. With 5 of those fixture you are below 10A, so you have a lot of leeway.

 

[pattenp]

Re: How many on a circut?

Two blacks, two whites, yes that is two ballast in there. That I know of, they don't make a single ballast that will drive 6 tubes.

Don't know if that is your light or someone else's but please do something about that cobbled together wiring with no box. and Romex dangling in the open.

Charles

Charles, I thought that's how stuff is wired in the deep south.

 

[Charles (in GA)]

Re: How many on a circut?

Charles, I thought that's how stuff is wired in the deep south.

I suppose that there are rednecks in SOUTHERN Indiana too. Its not something reserved just for the southern tier of states.

But hey, it works, and hasn't burned down yet. Could be worse, it isn't hidden in a wall or ceiling, out of sight.

Charles

 

[Charles (in GA)]

Re: How many on a circut?

A 15A wall switch is fine with only having the 5 fixtures. FYI, the total light load should not exceed 80% or 16A on the 20A circuit. With 5 of those fixture you are below 10A, so you have a lot of leeway.

Ya know, we harp so much on using the correct wire size for the breaker size, how the breaker protects the circuit, cannot use even a pigtail of 14 gauge to something in a 20 amp circuit, and yet, we stick 15 amp rated switches in a 20 amp circuit without even "batting an eye". Why is that? I know code specifically allows 15 amp receptacles in a 20 amp circuit, but I've never seen any mention of switches.

I have always been careful to use good quality switches, of the proper ratings for the circuit (or better) but I know not everyone does this.

Charles

 

[theoldwizard1]

Re: How many on a circut?

You might think about checking the breaker panel manufacturer catalog for special fluorescent breaker for that circuit. I don't know what is different about that type of breaker, but I do know that Square D does make them for their QO load centers.

 

[pattenp]

Re: How many on a circut?

Ya know, we harp so much on using the correct wire size for the breaker size, how the breaker protects the circuit, cannot use even a pigtail of 14 gauge to something in a 20 amp circuit, and yet, we stick 15 amp rated switches in a 20 amp circuit without even "batting an eye". Why is that? I know code specifically allows 15 amp receptacles in a 20 amp circuit, but I've never seen any mention of switches.

I have always been careful to use good quality switches, of the proper ratings for the circuit (or better) but I know not everyone does this.

Charles

I use 20A switches on 20A lightlng circuits. The only NEC section I recall is 404.14 and it just specifies the switch to be rated to the load. The exception is if the switch is controlling an outlet on a general purpose branch circuit then the switch needs to be rated no less than the over current device protecting the circuit.

 

[theoldwizard1]

Re: How many on a circut?

Ya know, we harp so much on using the correct wire size for the breaker size, how the breaker protects the circuit, cannot use even a pigtail of 14 gauge to something in a 20 amp circuit, and yet, we stick 15 amp rated switches in a 20 amp circuit without even "batting an eye". Why is that? I know code specifically allows 15 amp receptacles in a 20 amp circuit, ...

Yeah, why is that ?

When I wired my son's garage I used all 20A GFCI and receptacles.

Just finished wiring my daughter's kitchen. The counter top circuits were all 12 gauge, 20A and we actually bought 20A GFCI (because they were protecting multiple receptacles) but the rest of the receptacles were just plain 15A.

The garbage disposer is on a 20A circuit, and I did use a 15A switch.

 

[pattenp]

Re: How many on a circut?

If you think about it you can't plug in a device that is rated to take more than 15A into a 15A outlet because the device most likely will have a true 20A plug with the sideways blade. That's why you can use 15A and 20A outlets on a 20A circuit, but shouldn't put 20A outlets on a 15A circuit.

 

[Charles (in GA)]

Re: How many on a circut?

Yeah, why is that ?

When I wired my son's garage I used all 20A GFCI and receptacles.

Just finished wiring my daughter's kitchen. The counter top circuits were all 12 gauge, 20A and we actually bought 20A GFCI (because they were protecting multiple receptacles) but the rest of the receptacles were just plain 15A.

The garbage disposer is on a 20A circuit, and I did use a 15A switch.

Look closely at the GFCI or the box it came in, you will find the feed thru on a 15amp GFCI is almost always rated at 20 amps, so there is no real need to buy a 20 amp GFCI receptacle.

Buying a quality made 20 amp receptacle vs the identical quality made 15 amp receptacle will get you....... nothing, except the cross slot for a true 20 amp plug. The insides of any good spec grade, commercial grade or industrial grade 15 and its cousin 20 amp receptacle are exactly the same parts, just a different face plate snapped onto it.

I know others have said different, but I find in retail situations (Home Depot, Lowes, the local hardware store) that a 20 amp receptacle will cost more, usually around a dollar more, than the comparable 15 amp version, so no real reason other than they can charge it.

I have bought the last receptacles I will need for a long time to come, at the Flea Market, 20 amp commercial Hubbell backwire ones (two boxes of ten each bulk packed) and switches, (10 ea of Hubbell 20 amp switches, again bulk packed) so I won't need to buy any from the local big box I hope.

Charles

 

[Norcal]

Re: How many on a circut?

You might think about checking the breaker panel manufacturer catalog for special fluorescent breaker for that circuit. I don't know what is different about that type of breaker, but I do know that Square D does make them for their QO load centers.

Your thinking of a SWD breaker, they are only required where a circuit breakers is used to switch fluorescent lighting, use a switch & there is no requirement to use them. The same thing applies to HID lighting, if the breaker is used to switch them, then a HID rated breaker is required.