Residential Lighting Circuit

Status
Not open for further replies.
brian john said:
Do you have kids? 3 hours or more heck 24 X 7 in their bedrooms and bathrooms. Unless I hit the switch.
Click to expand...

Even so, is any residential circuit loaded to the full ampacity for 3 hours or more? I doubt it. You'd have an awfully high electric bill if it was.
 
brian john said:
Bob:

Do you have kids? 3 hours or more heck 24 X 7 in their bedrooms and bathrooms. Unless I hit the switch.
Click to expand...

Yes I do, I also have a lot of CFLs installed and may be installing motion sensors soon if they can not learn to shut out the lights. :D

That said, Peter is thinking like I am.

To meet the NEC definition of continuous load the maximum load would have to be on longer then 3 hours.

Considering that most dwelling unit lighting circuits also include receptacles it is very unlikely that the maximum load will ever be applied longer than 3 hours.

If the circuit happens to be only lighting then all the fixtures would have to be on at the same time for more then 3 hours at a shot.

So if the circuit feeds lighting in three bedrooms each with a closet light, the chances of it all being on together for 3 hours is pretty slim.

Keep in mind continuous load or not I am conservative with circuit loading usually shooting for 10 to 12 amps of lighting on a 20 amp circuit. :)
 
iwire said:
Yes I do, I also have a lot of CFLs installed and may be installing motion sensors soon if they can not learn to shut out the lights. :D
Click to expand...

The CFLs will make all the difference in the world with that electric bill of yours ;)

Considering that most dwelling unit lighting circuits also include receptacles it is very unlikely that the maximum load will ever be applied longer than 3 hours.
Click to expand...

I'm not following. Unless those receptacle loads aren't also on 24x7 (try getting the kids to shutdown the computer when they are asleep, along with turning off the TV, stereo, and everything else).

There are a lot of stupid little loads that all slowly add up. A small TV, cable box, stereo, computer and CRT monitor -- not that unheard of for teenagers -- starts to add up and is easily more than the lighting load. So, if you put 8 or 10 amps worth of lighting on the 2 or 3 "children's rooms", when you start putting teenagers in rooms, you've got another 8 or 10 amps worth of junk. Fortunately, as I'm sure you've now learned, CFLs really do cut down on the lighting loads. Now, if the teenager would just cut down on leaving everything else turned on ...

If you want to find out how much power things really consume, spend some time talking to environmentalists and off-grid folks.
 
tallgirl said:
I'm not following.
Click to expand...

Because you are over thinking it. :grin:

You are trying to make sense of it and I am pointing out how the NEC is worded.

In the case of a mixed use (lights & Plugs) circuit what is the 'maximum load' possible?
 
iwire said:
In the case of a mixed use (lights & Plugs) circuit what is the 'maximum load' possible?
Click to expand...

Plugs? ;)

I usually put 2 bedrooms on a 15 amp circuit, assuming the house has central air or the bedrooms are fairly small. I can assure anyone that the load in 2 bedrooms will never even come close to maxing out the circuit.
 
bradleyelectric said:
Might want to check out Leviton Vizia series. You can turn out the kids lights before 3 hours without having to get up!!
http://www.leviton.com/OA_HTML/ibeCZzpHome.jsp?minisite=10024&respid=22372
Click to expand...

Another product that's out there that I looked at recently is called "GreenSwitch" -- www.greenswitch.tv

It works by turning "off" receptacles when you leave. So if, for example, you've got a cable box that takes 100w on standby -- which mine seems to do -- you can turn it, and the television that's drawing another 50 to 100 watts on standby completely off. Then when you return, you flip a switch and all the little convenience items that suck hundreds of watts in total come back to life.

It's a pretty spendy system -- the basic "package" lists for about $1,200 -- but for someone with a lot of gadgets that suck power when turned "off", it might be one way to cut down on the bill.
 
tallgirl said:
So if, for example, you've got a cable box that takes 100w on standby -- which mine seems to do -- you can turn it completely off. Then when you return, you flip a switch and all the little convenience items that suck hundreds of watts in total come back to life.
Click to expand...


YEh, like I would want to wait 10-15 mins for my set top box to re-boot... I think not...:grin:
 
iwire said:
Because you are over thinking it. :grin:

You are trying to make sense of it and I am pointing out how the NEC is worded.

In the case of a mixed use (lights & Plugs) circuit what is the 'maximum load' possible?
Click to expand...

A bazillion.

What's the maximum permissible continuous load? 16A on a 20A circuit, 12A on a 15A circuit. I read the OP's as asking if you should consider the lighting a continuous load, and I think the answer is "Yes". Not that I think it makes a bit of difference. I think the problem comes back to another favorite argument -- what's the maximum number of rooms on a 20A branch circuit?

Work backwards from teenager bedroom loads and you'll see that a 12A continuous load for "two bedrooms on a 15A circuit" isn't hard. Put a TV with digital cable box and and stereo in one corner, desktop computer playing on-line games with a 19" CRT and a 75w desk lamp in the other corner, and 4 @ 60w lights in the ceiling. Turn them all on, be a teenager and leave them all on, and that's it. You have 315 watts of lighting load, another 300 watts (or more if it's a high-end gaming system) for the computer, and another 300 watts or more for the TV, cable box and stereo. That's over 900 watts in one room, times 2 bedrooms is 1,800 watts, and that's more than 12A @ 120VAC, and not that far from 16A.

In practice does it make a difference? No, and for the reason Peter gave -- it costs money and parents are going to scream at kids who do that.
 
stickboy1375 said:
YEh, like I would want to wait 10-15 mins for my set top box to re-boot... I think not...:grin:
Click to expand...

Neither do I. Which is why I'm not going to buy one of them ;)

If you want to see a fun little applet, check this out -- Julie's Electric Meter

I'm not convinced $1,200 for an 'energy saving' system that savings a few KWH per day on parasitic losses is going to pay itself off in 2 years like they claim. Much cheaper to put a plugin lamp timer on the receptacle and turn the cable box off that way.

They want $90 for a split receptacle. NINETY DOLLARS! I put CFLs in all the bedrooms and the den and bathrooms, I think, for $90.
 
andinator said:
I like to make them out in Spanish sometimes to match the others I find in this city in new homes.:cool:
Click to expand...
Ones I've seen:
Flod layt - flood light
Gsmokon - smokes
Ati - attic
Plougs danoung - Dining room plugs
Utili- utility
 
Status
Not open for further replies.
Top