garage door opener

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peugnetl

Member
Hello:
I am trying to calculate the demand Load requirements for a 1900 SF single family home.
I've gotten to the point where the "Fastened-in-place appliances" are calculated, well, their rating. However, I see no mentioned where to place the garage door opener. After all, the motor for this equipment is fastened to the frame of the roof of the garage.
I will like to know where to add this equipment because if it needs to go under this "appliances" matrix, it will be my fourth unit and according to the NEC (220.17) I must multiply the total volt-amperes by 75% when calculating for four or more units.
Can anyone help?
Thanks.
 

tonyi

Senior Member
Re: garage door opener

220.17 doesn't force you to do 75%, it permits you to use 75% - big difference :D
 

charlie b

Moderator
Staff member
Location
Seattle, WA
Occupation
Electrical Engineer
Re: garage door opener

This one I?ve not come across before, and it is certainly open to debate. It might wind up being an AHJ call. 220.17 does not require that the four ?fixed in place appliances? be hard wired. In fact, it gives washers and air conditioners as examples. I also see that a garage door opener might well fit into the NEC definition of ?appliance.? Nevertheless, I am disinclined to take credit for the garage door opener, if I were looking for the fourth appliance that would allow me to take advantage of the 75% demand factor. Rather, I would tend to consider this item to be in the same category as a floor lamp ? its load is accounted for as part of the lighting and receptacle outlet load (i.e., the 3 watts per square foot). I fully realize that if you are driving into your garage, you are not going to be running the trash compactor at the same time. So I can?t defend this position by citing NEC references; it?s just what seems right to me. Any other views?
 
G

Guest

Guest
Re: garage door opener

Hey charlie just to mudlle this up further say you come home and your wife is already home and is has the diswaher running, the compactor is cycling and shes using the disposal and then you come home and use the garage door opener. Then what?
 

jimwalker

Senior Member
Location
TAMPA FLORIDA
Re: garage door opener

He will be ok because she turned the tv off in the living room.Could maybe install a warning light on that disposal over the garage door so he waits to push the button. LOL
 
G

Guest

Guest
Re: garage door opener

Is the warnining lite a code requirement or just to alert charlie?
 

jimwalker

Senior Member
Location
TAMPA FLORIDA
Re: garage door opener

just to alert him of this overload condition.If he installs it make sure it meets code LOL
Kind of like GREEN ACRES
can just see all these warning lights as to whats running :D

[ January 29, 2004, 01:46 PM: Message edited by: jimwalker ]
 

steve66

Senior Member
Re: garage door opener

I find it hard to believe a garage door is going to make a big difference in the size of the service. After all, it will be a very intermitent load. I would have no problem applying a %75 demand factor to 4 of them. I know everyone gets off work at 5:00, but what are the odds of everyone opening their doors at the same time with all the AC units and garbage units all running. Even if they did, the openers would run less than a minuite, not enough time to heat up any feeders enough to wory about.

Not exactly approved by the code, but if they are 1/2HP or less, throw any guestimate at their load and move on.

Steve
 

jimwalker

Senior Member
Location
TAMPA FLORIDA
Re: garage door opener

1900 sq ft unless some way out stuff will easily make it.Now if your going to have a 3 stage tankless water heat for 24 kw then there might be a problem.Given normal loads your fine
I am assuming a 200 amp service

[ January 29, 2004, 06:14 PM: Message edited by: jimwalker ]
 
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