Dishwashers and Disconnects

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infinity

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In the 2011 NEC 422.31 has been re-written to include Appliances Rated over 300 VA and Motor Operated Appliances Rated Over 1/8 HP. This eliminated the confusion generated by 422.32 which has been removed from the code text.

My question is regarding dishwashers, do they generally have motors rated at 1/8 HP or greater? If so then I'm asuming that breaker lock outs are out as the exception to a disconnecting means within sight.

422.31(B) Appliances Rated over 300 Volt-Amperes. For permanently
connected appliances rated over 300 voltamperes,
the branch-circuit switch or circuit breaker shall
be permitted to serve as the disconnecting means where the
switch or circuit breaker is within sight from the appliance
or is capable of being locked in the open position. The
provision for locking or adding a lock to the disconnecting
means shall be installed on or at the switch or circuit
breaker used as the disconnecting means and shall remain
in place with or without the lock installed.
Informational Note: For appliances employing unit switches,
see 422.34.
(C) Motor-Operated Appliances Rated over 1⁄8 Horsepower.
For permanently connected motor-operated appliances
with motors rated over 1⁄8 horse power, the branchcircuit
switch or circuit breaker shall be permitted to serve
as the disconnecting means where the switch or circuit
breaker is within sight from the appliance. The disconnecting
means shall comply with 430.109 and 430.110.
Exception: If an appliance of more than 1⁄8 hp is provided
with a unit switch that complies with 422.34(A), (B), (C), or
(D), the switch or circuit breaker serving as the other disconnecting
means shall be permitted to be out of sight from
the appliance.
 

dana1028

Senior Member
Rob - this may be a regional thing.

Yes - dishwashers do have motors greater than 1/8 HP [at least the ones I've seen], but in my area I have only seen cord-and-plug connected dishwashers [dwelling units] so this 'disconnect in sight from' is not an issue.

All the commercial jobs I've seen have always had the disco next to the equipment.
 

infinity

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New Jersey
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For the longest time we simply hardwired dishwashers. Then we hardwired them with breaker lockouts. Now it appears that the breaker lockouts will no longer be permitted if the motor is larger than 1/8 HP.
 

Dennis Alwon

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Location
Chapel Hill, NC
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Retired Electrical Contractor
For the longest time we simply hardwired dishwashers. Then we hardwired them with breaker lockouts. Now it appears that the breaker lockouts will no longer be permitted if the motor is larger than 1/8 HP.

I never used a breaker lockout for anything. I generally dislike that rule since a lock does not have to be available. I much rather have a disco where I can see it.
 

goldstar

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Location
New Jersey
Occupation
Electrical Contractor
I never used a breaker lockout for anything. I generally dislike that rule since a lock does not have to be available. I much rather have a disco where I can see it.
I'm with you on this. After we hard-wire a DW, in all probability we're not going to be the ones to do any repairs on the unit. That leaves a plumber or an appliance repair guy. You have to hope that they have enough intelligence to go to the breaker panel and turn off the breaker before working on the unit. With respect to breaker lock-outs, I'm sure the plumber or the repair guy will figure out how to operate the device. On the other hand I've found it difficult explaining to a homeowner (over the phone) how to find a tripped breaker and then reset it. Adding a permanantly installed lock-out device adds a new wrinkle to the equasion. I like the receptacle inside the sink cabinet with a cord and plug attachment method.
 

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
hard wiring dishwasher makes it harder for the repair guy to pull out the unit for repair. doesn't it?
I am asking because I have never hardwired a dishwasher.
 

Little Bill

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Location
Tennessee NEC:2017
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Semi-Retired Electrician
hard wiring dishwasher makes it harder for the repair guy to pull out the unit for repair. doesn't it?
I am asking because I have never hardwired a dishwasher.

Not much harder, the unit JB is in front, 1 screw for the cover, then remove wirenuts and wires + EGC, you're disconnected!
 

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
Not much harder, the unit JB is in front, 1 screw for the cover, then remove wirenuts and wires + EGC, you're disconnected!

Then if the repair person wants to test it he has to put it back rewire it and try the unit. Any advantage hardwired VS plug in? So far i see plug in is more desirable than the hard wire.
 

goldstar

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Location
New Jersey
Occupation
Electrical Contractor
We're all assuming that the plumber or repair technician not only knows his trade but is also a rocket scientist and that he has the integrity to go to the breaker panel to shut off power. I've seen instances where they've taped or wire-nutted the bare wire end and tried to pull it through the RX connector just so they wouldn't have to make a trip to the breaker panel to power down and up. IMHO, the cord and plug is the most fool-proof.
 

S'mise

Senior Member
Location
Michigan
I don't know of an advantage to hard wiring but sometime you have no choice.
Got to follow installation instructions. IMHO, I think the code should say that if you use cord and plug it has to be accessable (under sink).
 

infinity

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Location
New Jersey
Occupation
Journeyman Electrician
Judging from most of the responses there are a lot of guys using cord and plug connected dishwashers. My question is where do you find the cord and plug? The last dishwasher that I cord and plug connected made no mention of cord and plug in the instructions, the store that sold it had no idea about where to get one and so as a last resort I bought one from Home Depot. It using a cord and plug on a dishwasher in a compliant manner as easy as everyone is making it sound?
 

S'mise

Senior Member
Location
Michigan
Where do you find the cord and plug? On the end of the appliance the way it came from the factory. If the instructions do not mention a cord and plug you hardwire it. Technically, I'd say it's a violation to just add your own cord.
 

infinity

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Location
New Jersey
Occupation
Journeyman Electrician
Where do you find the cord and plug? On the end of the appliance the way it came from the factory. If the instructions do not mention a cord and plug you hardwire it. Technically, I'd say it's a violation to just add your own cord.

That's what I thought but given the number of times I've heard of guys cord and plug connecting them I was wondering if most of these installs are in fact violations.
 

Howard Burger

Senior Member
stove and dryer cords

stove and dryer cords

Don't recall right off doing a dishwasher without a cord - been awhile since I did resi trim out, but I can't ever recall doing a stove or dryer where I haven't had to install the cord. So, was I in violation by providing the cord for these appliances?
 

infinity

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Location
New Jersey
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Journeyman Electrician
Don't recall right off doing a dishwasher without a cord - been awhile since I did resi trim out, but I can't ever recall doing a stove or dryer where I haven't had to install the cord. So, was I in violation by providing the cord for these appliances?

Here's the cord requirement. What do you think?

422.16(B)(2) Built-in Dishwashers and Trash Compactors. Built-in dishwashers and trash compactors shall be permitted to be cord-and-plug-connected with a flexible cord identified as suitable for the purpose in the installation instructions of the appliance manufacturer where all of the following conditions are met:
(1) The flexible cord shall be terminated with a grounding-type attachment plug.
Exception: A listed dishwasher or trash compactor distinctly marked to identify it as protected by a system of double insulation, or its equivalent, shall not be required to be terminated with a grounding-type attachment plug.
(2) The length of the cord shall be 0.9 m to 1.2 m (3 ft to 4 ft) measured from the face of the attachment plug to the plane of the rear of the appliance.
(3) Receptacles shall be located to avoid physical damage to the flexible cord.
(4) The receptacle shall be located in the space occupied by the appliance or adjacent thereto.
(5) The receptacle shall be accessible.
 

S'mise

Senior Member
Location
Michigan
I agree. A lot of these installs probably dont use the proper cord type, size, or strain relief fitting. (cord grip)

400.7(A)(8) Appliances where the fastening means and mechanical
connections are specifically designed to permit
ready removal for maintenance and repair, and the
appliance is intended or identified for flexible cord
connection


I take that to mean in a round about way "if the instructions say so"
 

S'mise

Senior Member
Location
Michigan
No, it's ok to do if you follow art 400. and 422.
I think the key here is "the installation instructions of the appliance manufacturer"
If they say "cord" you are fine.

I think a dishwasher cord should be SOW or other heavy duty cord listed for a wet location. I think alot of cords get smashed pushing the DW into the opening.
 

Little Bill

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Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
Judging from most of the responses there are a lot of guys using cord and plug connected dishwashers. My question is where do you find the cord and plug? The last dishwasher that I cord and plug connected made no mention of cord and plug in the instructions, the store that sold it had no idea about where to get one and so as a last resort I bought one from Home Depot. It using a cord and plug on a dishwasher in a compliant manner as easy as everyone is making it sound?

I just replaced mine a few months ago. I just looked in the install instructions and it said to "use UL Listed power cord kit part #xxxxxxx, marked for use with dishwasher"
I just went to their website and this is what I found!:confused:

CORD-POWER 3370315RP Whirlpool

Click image(s) to enlarge
CORD-POWER
CORD-POWER

Manufacturer: Whirlpool

Part# 3370315RP

Sale Price: $9.44
Add to Cart: Add To Cart

out of stock
 

JDB3

Senior Member
Jdb

Jdb

99.9% of the time, I put a duplex receptacle (feed with 12/3 w/g with 2 single pole breakers connected with a handle tie) under the sink for the disposal & dishwasher and mark the plate which receptacle is for which appliance. I use single pole breakers so that if one does trips, then you know which one is causing the problem.
 

John120/240

Senior Member
Location
Olathe, Kansas
One circuit for the disposal & one for the Dishwasher is overkill if you ask me.

One circuit for both is adequate. If the breaker does trip, you only have two

choices which one it is. To each his own method.
 
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