garbage disposals on dedicated circuit?

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Joseph Alexander

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Im aware that most AHJs require that GBs and DWs be on dedicated circuits. But what code is this? The way I read it 430.53 applies because all new residential garbage disposals have their own integral OCPD, its the reset button under the unit, therefore they don't have to be on a dedicated circuit.
A little help on the code for this please!
 
Take a look at 210.23(A)(2).

This section is dealing with permissible loads on 15 and 20 amp branch-circuits.

210.23(A)(2) Utilization Equipment fastened in place. The total rating of utilization equipment fasted in place, other than luminaires (lighting fixtures), shall not exceed 50 percent of the branch circuit ampere rating where lighting units, cord and plug connected utilization equipment not fastened in place, or both, are also supplied.

So if the garbage disposal load exceeds 50% of the branch circuit rating then you can't connect anything else to the circuit.

Chris
 
430.53(A)(1) perhaps?

One of the conditions to apply 430.53(A) is that ALL 3 conditions are met:
(1) The full-load rating of each motor does not exceed 6 amperes.
(2) The rating of the branch-circuit short-circuit and ground-fault protective device marked on any of the controllers is not exceeded.
(3) Individual overload protection conforms to 430.32.

I looked at the specs for 9 Insinkerator models available (http://www.insinkerator.com/isejsp/product/selector.jsp)
  • The amp rating ranges from 6.7 - 10.2 A ...they call it an "Amp. (Avg. Load):10.2", not sure how that translates into full-load.
  • All were 1hp or less
  • No menton on individual OCPD, thermal protector, etc
I don't know what particular product you are installing - Insinkerator, Kenmore/Sears, WasteKing, etc ... but I would start by looking at the amp rating.
 
I used to put them on the same circuit w/o much fret, until I did a house that spec'd a disposal rated a 13 amps. I was very cautious from there on out. Most of the time now, if they are close enough together, I will run it 12-3.
 
raider1 said:
Take a look at 210.23(A)(2).

This section is dealing with permissible loads on 15 and 20 amp branch-circuits.

210.23(A)(2) Utilization Equipment fastened in place. The total rating of utilization equipment fasted in place, other than luminaires (lighting fixtures), shall not exceed 50 percent of the branch circuit ampere rating where lighting units, cord and plug connected utilization equipment not fastened in place, or both, are also supplied.

So if the garbage disposal load exceeds 50% of the branch circuit rating then you can't connect anything else to the circuit.

Chris
Click to expand...

210.23 only applies where there are lights and other equipment not fastened in place, on the same circuit as the equipment that is fastened in place. This is a good question so I looked it up in the Handbook. 210.52(B) won't allow a disposal or dishwasher to be on the small appliance circuits that feed the kitchen outlets. The only other alternative is to put the dish & disp on the same circuit. I've seen this done but nowadays with dishwashers pulling 11 amps or more, that doesn't seem like a good idea. I always use 12/3 for the dish & disp. See also 210.52(B)(1) and (B)(2).
 
It is interesting to me because disposals are on for such a short period of time that I doubt that the circuit would trip due to overload even if the dishwasher and disposal were on together.

This being said I usually wire the disposal and the kitchen uc lights on the same circuit. Or I run a separate 15 amp circuit to the disposal. Usually the disposal isn't picked out until the last minute so we can't get specs on them but I have never been called back to my job or any other job because of overload with a disposal and another appliance on the same circuit.
 
Dennis Alwon said:
This being said I usually wire the disposal and the kitchen uc lights on the same circuit.
Click to expand...
I would be hesitant to combine a motor load with undercabs in the same kitchen. Have you ever had any complaints about lights dimming?
 
Never. Besides how often is the disposal on--- Seconds in most instances. Perhaps they do dim a bit but I have not heard about it.
 
Hey guys happy easter. I've been here way back when but I'm back again, not an expert but trying to learn. My .02, we always seperate the dw and gd. Some ahj's are requireing a switch for the dw on the counter. If either ever cause the ocpd to open, you have to check both or you may get lucky and find the problem right away.

Hank
 
I don't know if my reply came up. Happy easter every one, I've been here before, way before and now I'm back, not an expert like most here but willing to throw some logs on the fire. As far as gd's and dw's it's good practice to seperate the circuit, but does code allow to put them on the counter sa's?

Hank
 
elechank said:
I don't know if my reply came up.
Click to expand...
Yeah, your first couple posts will be invisible to you for a short time. Since they both said something a little different, they both stayed. Welcome back. :)

...does code allow to put them on the counter sa's?
Click to expand...
Nope. The SABCs are for counters, walls and fridge receptacles (210.52(B)(1)) and nothing else (210.52(B)(2)). :)
 
12/3

12/3

I have always gone the 12/3 route. Installed separate switches for each device near the sink. (Once again that motor disconnect rule comes to mind). Now I still run the 12/3 but cord and plug each unit. Dennis's idea about going to the UC lighting sounds good to me.
Thanks,
Fran
 
My UC lights are generally on with kitchen lighting, so that is not an option for me, as I am hesitant to put any sort of motor load on with a lighting circuit. Safe bet is to separate them on individual circuits. One question to ask is, do you bill them separate, or do you usually include in a base price. That decision is a factor as much as anything, IMO.
 
I will either share a 20a circuit for both, or separate 15a circuits for each.


raider1 said:
Take a look at 210.23(A)(2).

210.23(A)(2) Utilization Equipment fastened in place. The total rating of utilization equipment fasted in place, other than luminaires (lighting fixtures), shall not exceed 50 percent of the branch circuit ampere rating where lighting units, cord and plug connected utilization equipment not fastened in place, or both, are also supplied.

So if the garbage disposal load exceeds 50% of the branch circuit rating then you can't connect anything else to the circuit.
Click to expand...
I disagree, because " . . . lighting units, cord and plug connected utilization equipment not fastened in place, or both . . . " does not fit the description of a dishwasher, which IS fastened in place.
 
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donselec said:
210.23 only applies where there are lights and other equipment not fastened in place, on the same circuit as the equipment that is fastened in place.
Click to expand...

Correct, the original post never said that he was combining the dishwasher and the garbage disposal on the same circuit, only what code dealt with requiring the garbage disposal and dishwasher being required to be on their own circuit. The reason that I posted section 210.23(A)(2) is that in my area it is common pratice to install the light over the kitchwen sink on the same circuit that the garbage disposal is on, and install a separate circuit for the dishwasher.


Chris
 
I also use one 20 amp circuit for dw and disp. and always cord and plug both at the same split receptacle. never had a problem , If its not code compliant no one has to this point ever called it.
 
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