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Old 06-29-2011, 03:30 PM   #16
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Garbage disposal circuit


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Originally Posted by rjniles View Post
brric,

I think you teed off electures, he has not made another post since you called him on the OCPD requirements for the garbage disposers.
Just trying to get the correct information out there.
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Old 07-08-2011, 09:22 PM   #17
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Originally Posted by brric View Post
That is TOTAL BS. You do not calculate residential appliance motor circuits using motor calculations.
Read NEC 430.6 in totality. Especially the exceptions.
Sorry for the delayed response. Just got back from vacation.

Where exactly in the NEC is there any kind of exceptions for residential appliance motor circuits?


422.3 Other Articles.
The requirements of Article 430 shall apply to the installation of motor-operated appliances, and the requirements of Article 440 shall apply to the installation
of appliances containing a hermetic refrigerant motor-compressor(s), except as specifically amended in this article.

As for 430.6(A)(1) exceptions lets take a look at exception 3;

Exception No. 3: For a listed motor-operated appliance that is marked with both motor horsepower and full-load current, the motor full-load current marked on the nameplate
of the appliance shall be used instead of the horsepower rating on the appliance nameplate to determine the ampacity or rating of the disconnecting means, the branchcircuit
conductors, the controller, the branch-circuit shortcircuit and ground-fault protection, and any separate overload protection.


Article 100 definitions reads;

Appliance. Utilization equipment, generally other than industrial, that is normally built in standardized sizes or types and is installed or connected as a unit to perform one or
more functions such asclothes washing, air conditioning, food mixing, deep frying, and so forth.


A garbage disposal is a purely a motor so exception 3 does not apply.

Now, just for the sake of arguement (and I know there will be) lets say that exception 3 does apply.


Exception No. 3: For alisted motor-operated appliance that is marked with both motor horsepower and full-load current, the motor full-load current marked on the nameplate of the appliance shall be used instead of the horsepower rating on the appliance nameplate to determine the ampacity or rating of the disconnecting means, the branchcircuit
conductors, the controller, the branch-circuit shortcircuit and ground-fault protection, and any separate overload protection.

Looking at the information provided by the OP;

Amp loads are 6.9 and 8.1

Insinkerator 5
6.9 x 125% = 8.625 amps. #14 awg is needed.

6.9 x 250% = 17.5. A 20 amp breaker can be used.

Insinkerator 5X
8.1 x 125% = 10.125. #14 awg is needed.

8.1 x 250% = 20.25. A 25 amp breaker can be used.

However, since exception 3 does not apply my original post is correct.

On a side note, if I encountered this on the job I would run seperate #14 circuits with 15 amp breakers on each. If the larger motor tripped the breaker during use, a larger breaker can be used.
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Last edited by electures; 07-08-2011 at 10:33 PM.
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Old 07-08-2011, 09:28 PM   #18
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Originally Posted by mpoulton View Post
Yeah, nobody sizes residential motor-based appliance circuits that way. Nor is there any good reason to. It wouldn't even be code compliant to use those breaker/conductor combinations if these disposals are cord-and-plug connected.

I'd install one 20A circuit for both of them. I'm not aware of any requirement that garbage disposals have a dedicated circuit. You can even add other receptacles on that circuit if you want to get more use out of it. However, you can't count it as one of the "small appliance circuits" required in a kitchen.

EDIT: brric makes a good point - the disposal instructions may call for a dedicated circuit to each.
Putting both disposals on one circuit is a violation of 430.53(A).
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Old 07-08-2011, 09:30 PM   #19
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Originally Posted by Anti-wingnut View Post
Thank you. I knew this was BS, but I was waiting for a real electrician to respond.

In my 30 years of industrial, commercial and multi-family construction, I have never seen a disposal protected with anything other than a 15 or 20 circuit breaker. The statement by our "Inspector" is ludicrous. Now you have residential wiring protected by a much bigger breaker than it safely should be.

This is the danger with so many of these sites, you get some "experts" who claim to be "State Electrical Inspectors" and some poor fool will listen to them


electures: You're a fool if as a inspector you can't tell someone how to safely wire a garbage disposal
430.6 (A) (1) exception #3 - correct?

Incorrect. Try reading the NEC.
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Old 07-08-2011, 09:37 PM   #20
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[quote=NJMarine;675701]430.6 (A)(1) Exception No. 3: For a listed motor-operated appliance that is marked with both motor horsepower and full-load current, the motor full-load current marked on the nameplate of the appliance shall be used instead of the horsepower rating on the appliance nameplate to determine the ampacity or rating of the disconnecting means, the branch-circuit conductors, the controller, the branch-circuit short-circuit and ground-fault protection, and any separate overload protection.

They both could be run off a single 20 amp circuit.[/quote]



Putting them both on one circuit is a violation of 430.53(A).
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Old 07-09-2011, 12:53 AM   #21
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Originally Posted by NJMarine View Post
430.6 (A)(1) Exception No. 3: For a listed motor-operated appliance that is marked with both motor horsepower and full-load current, the motor full-load current marked on the nameplate of the appliance shall be used instead of the horsepower rating on the appliance nameplate to determine the ampacity or rating of the disconnecting means, the branch-circuit conductors, the controller, the branch-circuit short-circuit and ground-fault protection, and any separate overload protection.

They both could be run off a single 20 amp circuit.
Hell, you open up the book that comes with the GD, and it states the NEC & if lucky, the CEC, right there in the booklet.
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Old 07-09-2011, 12:56 AM   #22
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Hell, you open up the book that comes with the GD, and it states the NEC & if lucky, the CEC, right there in the booklet.
Greg, Check 430.53(A). I think you'll find I am correct. These two disposals cannot be on the same circuit.
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Old 07-09-2011, 12:59 AM   #23
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Putting both disposals on one circuit is a violation of 430.53(A).
Doubtful that the OP is doing a commercial installation. I am going to trust the other that work in the industry, and by what the manufacturer recommends, than someone that keeps quoting the NEC, like a TV evangelist quoting scripture. Hell, the Mormons know more about the bible, than most that minister, but that does not meant they are experts, even though they have read a lot, and listened to those that preach to them. It stands the same way, that someone comes onto a forum preaching the NEC. If anyone has any doubts, the true experts on this forum will point the thread in the right direction, vs. someone that gets banned more than a virgin in cheerleading competition.
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Old 07-09-2011, 01:04 AM   #24
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Originally Posted by gregzoll View Post
Doubtful that the OP is doing a commercial installation. I am going to trust the other that work in the industry, and by what the manufacturer recommends, than someone that keeps quoting the NEC, like a TV evangelist quoting scripture. Hell, the Mormons know more about the bible, than most that minister, but that does not meant they are experts, even though they have read a lot, and listened to those that preach to them. It stands the same way, that someone comes onto a forum preaching the NEC. If anyone has any doubts, the true experts on this forum will point the thread in the right direction, vs. someone that gets banned more than a virgin in cheerleading competition.
Another poster suggested putting both on one circuit. Commercial or residential is irrelevant. Based on the size of these two disposals, they can't be on the same circuit.
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Old 07-09-2011, 01:12 AM   #25
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Again, you have no way of telling what is correct, and citing NEC is not going to solve it. Unless you work in the industry like some that are actually helping, vs. quoting NEC, it does not help out the OP. It actually confuses them. Hell, when I did this stuff 24/7, 365 days in the Navy, I usually went by gut instinct when trying to figure out why something did not work, vs. trudge up six decks to pull out a manual to tell me how to do my job, when I already knew how to do it, and the steps in doing it safely.

Quoting the NEC over and over, is not going to solve a person's problem, it is only going to confuse them, and cause them not to fix the issue, but delay it, or just put the job off, due to they feel that they are inadequate & under-educated to perform the task at hand. The manufacturer spells out in their instruction manuals the steps, the NEC & CEC guidelines, and even states in nice bold print, that if you do not know what you are doing, contact a professional.

Sorry to say this, but if they want to do a bubba, and risk life & property, so be it. The experts on these forums that do this, vs quote the NEC like you do, have done their job, and can not be there to keep the person doing it from the risks they take, because you at some point have to wash your hands that you did the best you could.
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Old 07-09-2011, 01:28 AM   #26
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Originally Posted by gregzoll View Post
Again, you have no way of telling what is correct, and citing NEC is not going to solve it. Unless you work in the industry like some that are actually helping, vs. quoting NEC, it does not help out the OP. It actually confuses them. Hell, when I did this stuff 24/7, 365 days in the Navy, I usually went by gut instinct when trying to figure out why something did not work, vs. trudge up six decks to pull out a manual to tell me how to do my job, when I already knew how to do it, and the steps in doing it safely.


Quoting the NEC over and over, is not going to solve a person's problem, it is only going to confuse them, and cause them not to fix the issue, but delay it, or just put the job off, due to they feel that they are inadequate & under-educated to perform the task at hand. The manufacturer spells out in their instruction manuals the steps, the NEC & CEC guidelines, and even states in nice bold print, that if you do not know what you are doing, contact a professional.

Sorry to say this, but if they want to do a bubba, and risk life & property, so be it. The experts on these forums that do this, vs quote the NEC like you do, have done their job, and can not be there to keep the person doing it from the risks they take, because you at some point have to wash your hands that you did the best you could.
I always thought the NEC was correct. Is there another way? Also, I actually do work in the industry everyday.
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Last edited by electures; 07-09-2011 at 01:31 AM.
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Old 07-09-2011, 07:49 AM   #27
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I always thought the NEC was correct. Is there another way? Also, I actually do work in the industry everyday.
The problem is you continue to give out incorrect information even when the coed citation to refute what you say is right in front of you.
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Old 07-10-2011, 09:48 PM   #28
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The problem is you continue to give out incorrect information even when the coed citation to refute what you say is right in front of you.
No, the problem is you and the other "real electricians" giving out incorrect information by citing 430.6(A)(1) ex. 3.

430.6 (A)(1) Exception No. 3: For a listed motor-operated appliance that is marked with both motor horsepower and full-load current, the motor full-load current marked on the nameplate of the appliance shall be used instead of the horsepower rating on the appliance nameplate to determine the ampacity or rating of the disconnecting means, the branch-circuit conductors, the controller, the branch-circuit short-circuit and ground-fault protection, and any separate overload protection.

A disposal is not a listed motor-operated appliance therefore this exception does not apply.

In the UL Scopes for Standards found here, is the UL Standard for Motor-Operated Appliances (UL73). It reads as follows;


Motor-Operated Appliances

UL 73


1 Scope


1.1 These requirements cover motor-operated appliances to be employed in accordance with the National Electrical Code, NFPA 70.
1.2 These requirements also cover small utilization appliances, such as vibrators in which motion of an operating part is produced by electrical means.
1.3 These requirements do not cover appliances rated more than 600 V; nor do they cover appliances involving universal motors rated more than 250 V.
1.4 These requirements do not cover equipment intended particularly for the control of electric motors; separator motors; nor electric clocks, fans, clothes dryers, washing machines, hair dryers, tools, waste disposers, dishwashers, office appliances and business equipment, refrigerators, air conditioners, vending and amusement machines, hair clippers and shavers, snow movers, automotive and garage equipment, or other motor-operated appliances that are covered by individual requirements.
1.5 An appliance that utilizes some other source of energy, such as gas or steam, in addition to electric energy will be investigated under these requirements and under such additional requirements as are applicable to the appliance under consideration.
1.6 Manually operated die-cutting machines without electrical parts need only comply with the following applicable requirements. Industrial machines of this type are not addressed by these requirements.
a) Protection Against Injury to Persons - Sections 32 - 36 and 41;
b) Performance - Section 58;
c) Markings - 70.1 (excluding electrical rating); and
d) Instruction Manual - Section 71.
Waste disposers are covered under UL Standard 430 and Article 430 of the NEC. My original post is correct.

Oh and also, pool filter motors are not "listed motor-operated appliances either. I will correct that post as well.
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Old 07-10-2011, 10:04 PM   #29
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Originally Posted by Anti-wingnut View Post
Thank you. I knew this was BS, but I was waiting for a real electrician to respond.

In my 30 years of industrial, commercial and multi-family construction, I have never seen a disposal protected with anything other than a 15 or 20 circuit breaker. The statement by our "Inspector" is ludicrous. Now you have residential wiring protected by a much bigger breaker than it safely should be.

This is the danger with so many of these sites, you get some "experts" who claim to be "State Electrical Inspectors" and some poor fool will listen to them

430.6 (A) (1) exception #3 - correct?

electures: You're a fool if as a inspector you can't tell someone how to safely wire a garbage disposal
Unfortunately none of the "real electricians" got it correct. And my "ludicrous" statement is code compliant.

And the reall danger of sites like this is the wanna-be's who think because they have over a thousand posts they think they know what they are doing. And as soon as somebody comes along and presents information that they disagree with, they start bashing them because they are to lazy to look it up. After all, that is how thay have done it for 30 years. Then there are the people who think that because they wired their own home, they are now qualified to give advice. And they probably don't even own a code book.
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Old 07-10-2011, 10:53 PM   #30
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The 3/4HP will need a dedicated #14 circuit with a 35A breaker.

The 1/2HP will need a dedicated #14 cicuit with a 25A breaker.

They are motors and the requirements are specific. If you want I would be happy to provide the calculations for each motor.
Interesting that in a different message from you when you show the actual caculations you state thus:

Quote:
Insinkerator 5
6.9 x 125% = 8.625 amps. #14 awg is needed.

6.9 x 250% = 17.5. A 20 amp breaker can be used.

Insinkerator 5X
8.1 x 125% = 10.125. #14 awg is needed.

8.1 x 250% = 20.25. A 25 amp breaker can be used.

In one message, you stated a 35 Amp breaker can be used, but in another one, only a 25 Amp breaker is needed. Which one did you intend?
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