Hello folks, I'm new to this group and look forward to exchanging information with fellow Electrical professionals. The questions I have are: When performing calculations for a residential service, should an allowance be made for garage door openers as fixed appliances in accordance with 220.17? What about ceiling fans? should any allowance be made for these beyond general lighting?
I recently did a load calc. and started scratching my head over the same load. My local inspector (who is a real code connoisseur and a great gut to go to if you want to chew the code)says yes. Figure the garage door openers as fixed appliances.
When I expressed my concerns with the vagueness of that section of the code as well as feeling that the load calc. section is a little outdated, he whole-heartedly agreed and thinks the who section needs an overhaul.
I didn't get his opinion about ceiling fans because it was already of my opinion to not list ceiling fans as fixed appliances. I figured they were included in the general lighting allowance of 3 VA per sq. ft.
Re: Allowance for garage door openers#87316 02/12/0412:27 PM02/12/0412:27 PM
Thanks, I think it makes sense that the Garage door openers are included. The ceiling fan can make for an interesting discussion though. I have a situation were there are only 3 appliances to consider and thus cannot apply the 75% demand. However, if I consider the ceiling fan an appliance, I now have the 4 or more fixed appliances necessary to allow application of the 75% demand. This results in a smaller load than if the fan is not included. So, there are situations where it may be advantagous to consider the ceiling fans as fixed appliances. For those who may argue that these fans are considered part of the general lighting load, I would ask why then is it that the only specific reference to ceiling fans is in article 422 APPLIANCES? Specifically article 422.18.
Re: Allowance for garage door openers#87317 02/12/0406:14 PM02/12/0406:14 PM
If this is any help, most newer garage door opener systems draw around 2-3 amps. I used to run a dedicated 20 amp circuit out to the opener as a matter of course, just because I was taught that was the way to do it by other companies I worked for back in the helper days. My current trend is still for a dedicated circuit, but now its a 15 amp one run with # 14. For my 2 cents, its general lighting load at 3 watts per sq. ft.
Re: Allowance for garage door openers#87319 02/13/0411:48 PM02/13/0411:48 PM
I know where you're coming from. If you take a step back and look at it that way, it may seem like splitting hairs. But I think the acual problem needs to have a second look also by taking a step back. I really feel there is so much haze in figuring these for residential that there is plenty of room to make a mistake.
I guess it is the NEC's vagueness & ambiguity that gives me so little confidence in a load calc.'s end result. I'm not so sure a mistake would make a difference either way. It kind of makes the whole formality feel kind of pointless.
Of course obviously there is a real point to doing an accurate load calc., but I have yet to find one that I can feel confident with. Or maybe I just need to know, trust, and understand the NEC's way better.
I guess I want to be able to come up with a number and say "this is your load". A number that I felt confident was not too far on either side of the line figuring too much or too little. But maybe it's just the nature of the beast. Because of diversity and demand factors it is too difficult if not impossible to have that theroretical or calculated number that is an accurate representation of the actual real load.
Re: Allowance for garage door openers#87323 02/16/0409:28 PM02/16/0409:28 PM