teco
New Member
Posts: 3
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Post by teco on Apr 21, 2016 3:00:15 GMT -6
What disconnecting means are some of you using to be NEC compliant for the connection to a dishwasher? A motor rated switch under the sink area, adjacent to the unit area, GFCI breaker, seems to be the best way, being that a particular cord set needs to be listed in the manufacturers instructions to use a cord and plug. Then there is accessibility. Any thoughts welcomed.
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Post by Electrical Code Academy Staff on Apr 21, 2016 7:08:06 GMT -6
Greetings Teco -
Typically on a dishwasher the disconnection means is the circuit breaker in the electrical panel. However, in many cases the installer also choose to use a plug and cord method to which the attachment plug would meet the disconnection means aspect of the installation.
Example :
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.
With that said when the cord and plug option is not selected then the following kicks in as you are aware.
(C) Motor-Operated Appliances Rated over 1⁄8 Horsepower. The disconnecting means shall comply with 430.109 and 430.110. For permanently connected motor operated appliances with motors rated over 1⁄8 hp, the disconnecting means shall meet 422.31(C)(1) or (2).
(1) 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. (2) The disconnecting means shall be installed within sight of the appliance.
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.
My personal preference (and that is just me) is to install a receptacle under the sink and the cord is permitted to penetrate the side of the counter (it is not a wall) and then plug into the receptacle with a defined and listed cord for the application. The GFCI protection to the branch circuit as defined in 250.8(D) will be located in the panel as my choice. The option to use a faceless GFCI at another location is always an option. As for the accessibility of the GFCI, I happen to fall in the camp where a GFCI placed under a sink area is not considered readily accessible....I don't discriminate and to be honest it the GFCI was under the counter my 78 year old mother would not have such ready access, however that is my opinion on that and I am sure others may disagree.
While it may be code accepted to use a snap switch as long as it complies with 430.109 and 430.110, it usually is not the standard practice to do so. The cord and plug or circuit breaker tends to be the solution of choice.
Hope this helps and if additional information is needed please feel free to post....and THANK YOU for being the FIRST POSTER on this new forum...Spread the Word !
Master The NEC
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teco
New Member
Posts: 3
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Dishwasher
Apr 21, 2016 18:55:32 GMT -6
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Post by teco on Apr 21, 2016 18:55:32 GMT -6
Interesting. So would you say if the manufacturer's instructions made no mention of a suitable cord set, we would then have to use a toggle switch under the sink? Also, what are your thoughts on a dishwashing unit on/off switch in reference to disconnecting the ungrounded conductor? I feel this particular section of the NEC could use a bit more clearity. Thx so much for your answers.
I had no idea I was a 1st poster! Been awhile since I was 1st at something. Lol.
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Post by Electrical Code Academy Staff on Apr 22, 2016 7:27:51 GMT -6
Teco - Many of the manufacturers do not supply their appliances with cords. They expect the end user or installer to supply them in most cases as an installation option. The majority of dishwashers sold simply come with an access point under the dishwasher and no cord attached. The installer at that point have the option to hard wire or cord and plug the dishwasher. You would not have to have a cord supplied by the dishwasher manufacturer to achieve a cord and plug installation.
However, the cord selected would have to be in compliance with Section 422.16(B)(2) which tells us the length requirements and that the cord must be listed for the application. Now, it states that the flexible cord has to be identified as suitable for the purpose in the installation instructions of the appliance manufacturer and so if they happen to state that no flexible cords can be used then your options are limited. However, it is my experience that they don't limit you in such a way.
Here is the exact installation instructions from Whirlpool....
If connecting dishwasher with a power supply cord:
■ Use Power Supply Cord Kit (Part Number 4317824) marked for use with dishwashers. Kit contents include:
– Volex, Inc., UL Listed 16 gauge 3 wire power supply cord with 3 prong grounded plug. – Neer C-500 ⁷⁄₈" strain relief. – 3 wire connectors. – Part Number 302797 grommet
Follow the kit instructions for installing the power supply cord.
■ Power supply cord must plug into a mating 3 prong, grounded outlet, located in the cabinet next to the dishwasher opening. Outlet must meet all local codes and ordinances.
So in Whirlpools case they suggest a specific cord.......now that meets the manufacturers recommended (listed) flexible cord and the NEC just makes sure that in the installation process that the rules pertaining to Section 422.16(B)(2) are observed. I think in most cases the manufacturer will either list a cord if they provide them like whirlpool does, because they are large enough to do so.. How here is the scary part......LG is a large manufacturer of Dishwashers and here is their installation instructions for the electrical portion of the install.
STEP 2: PREPARE ELECTRICAL WIRING 1. This appliance must be operated with correct voltage as shown in this manual and on the rating plate, and connected to a dedicated properly grounded circuit, protected by a time-delay fuse. Wiring must be 3 wires including ground. 2. If an outlet and a three-prong power cord is used, it should be in an accessible location adjacent to and no behind the dishwasher and within 4ft.(1.2 m) of the dishwasher side. 3. The wiring or cord must be grounded properly. If in doubt, have it checked by a qualified electrician. Do NOT connect any other appliance to the same outlet. 4. The wiring or cord must be routed as shown in Fig. 4 below. 5. Make sure electrical cable is oriented in the bottom channels as shown in the figure below.
Now what I find rather interesting in LG's instructions is the demands made in Step 2, item 1 for a "time-delay fuse".....so protecting it by a circuit breaker as usually done would kinda be against their instructions and if some say it is an internal fuse then Why Mention It.....its internal and part of the appliance. So are all the LG dishwashers out on the market in violation of NEC 110.3(B) when they are protected with a standard circuit breaker or now a GFCI Circuit Breaker is that is their protective (210.8(D)) choice.
My cord point is that some manufacturers may call a specific cord out and others just say a cord, you can find listed dishwasher cords so that is not an issue for this LG unit and the NEC section 422.16(B)(2) just keeps if under control in terms of the installation.
NOTE TO LG - I am available (part-time) to re-write your installation manual....it is a bit dated.
Forgot to address your question on the On/Off Switch option as defined in 422.34. I have no problems with it as long as the dishwasher meets the specific requirements of the rule. If the unit has a marked-off position (specifically) and it disconnects all ungrounded conductors as long as the other disconnection means are provided in accordance with 422.34(A)-(D) and in most all cases there will be. I personally do not have any issues wit the wording but I recommend submitting a public input for the 2020 cycle as I serve on that CMP and look forward to your input.
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teco
New Member
Posts: 3
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Dishwasher
Apr 22, 2016 14:08:12 GMT -6
via mobile
Post by teco on Apr 22, 2016 14:08:12 GMT -6
Got it. Thanks for all the info.
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Post by certifiedinspector on May 18, 2016 14:31:06 GMT -6
Good question.
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