Hot Water Heater Disconnect?

[stickboy1375]

I don't think Marc was talking 422.16.

I know marc wasn't talking about 422.16, that was my reason why is isn't legal...

BTW are you sure they are not listed for that, or like me you just never did it that way?

Insta-hots are solder in place and have cords. :smile:

If you can find one I'll eat crow! :grin:

 

[Dennis Alwon]

Technically, it is for the grounded conductor, not the grounding.

Again I ask what difference would it make? I know the difference between a grounded and grounding conductor but the device would be the same with perhaps a different configuration.

 

[iwire]

If you can find one I'll eat crow! :grin:

Enjoy

Electric storage type water heater, cord and plug connected.

Ariston 4-Gallon Electric Mini-Tank Water Heater

Next time you make a bet .... Google first. :grin:

 

[mdshunk]

I do not undestand.

What code would you cite?

I don't have the NEC on the computer I'm sitting on at the moment, but I remember that 410-58(D) from the '99 and earlier had a requirement that the ground prong be first-make, last-break. Throw 110.3(B) into the mix there too.

 

[480sparky]

Again I ask what difference would it make? I know the difference between a grounded and grounding conductor but the device would be the same with perhaps a different configuration.

It probably goes back to the listing of the device. A 3-wire dryer (10-30) receptacle is intended to provide both 120 and 240 volts, with the L-slot being the neutral.

A 6-30 is designed for strictly 240 volts and a ground.

 

[Dennis Alwon]

I don't have the NEC on the computer I'm sitting on at the moment, but I remember that 410-58(D) from the '99 and earlier had a requirement that the ground prong be first-make, last-break. Throw 110.3(B) into the mix there too.

How would any 220 volt receptacle, with ground, assure that rule. I don't get it.

 

[stickboy1375]

Enjoy

Electric storage type water heater, cord and plug connected.

Ariston 4-Gallon Electric Mini-Tank Water Heater

Next time you make a bet .... Google first. :grin:

It comes with a factory cord, I hope it is listed for it.... find one that does not come with a factory cord...

 

[mdshunk]

How would any 220 volt receptacle, with ground, assure that rule. I don't get it.

The ground pin/prong is slightly longer on plug caps that are intended to be used on a grounded circuit. It is a function of the plug, not the receptacle. The 3-wire dryer cord does not comply.

 

[Dennis Alwon]

It probably goes back to the listing of the device. A 3-wire dryer (10-30) receptacle is intended to provide both 120 and 240 volts, with the L-slot being the neutral.

A 6-30 is designed for strictly 240 volts and a ground.

I still don't see an issue with it however, that being said I always use fuseless discos or a 30 amp DP switch.

 

[480sparky]

How would any 220 volt receptacle, with ground, assure that rule. I don't get it.

Look at any cord end (the male end) with a ground prong. They are longer than the rest. That makes them first-make, last-break.

 

[M. D.]

There are many examples of similar attempts

17-19 Log #2729 NEC-P17 Final Action: Reject

(422.16(B)(5))
_______________________________________________________________
Submitter: Doug Boggus, City of Grand Prairie

Recommendation: Revise text to read:
422.16(B) Specific Appliances
(5) Water Heaters. Water heaters shall be permitted to be cord-and-plug
connected with a flexible cord identified as suitable for use on water heaters in
the installation instructions of the appliance manufacturer, where all of the
following conditions are met:
(1) The flexible cord is terminated with a grounding-type attachment plug.
(2) The length of the cord is not less than 610 mm (2 ft) and not more than
1.8 m (6 ft).
(3) The receptacle is accessible.
(4) The flexible cord is not subject to physical damage.
(5) The flexible cord has a temperature rating not less than that marked on
the appliance nameplate or in the appliance?s connection wiring compartment.
(6) The water heater is identified for cord-and-plug connection.

Substantiation: Throughout the US, jurisdictions are constantly approached to
allow water heaters to be connected to 120-volt and 240-volt power supply
through plug-and-cord connection in violation of 422.16(A) as such appliances
are generally not identified for flexible cord connection. The most commonly
proposed type cord is ?dryer cords? rated at 30-amperes for connections to 30-
50 gallon storage type units. This is because of local demand for a quick and
safe way to facilitate removal and replacement of such appliances. The
proposed wording is intended to set necessary requirements for installations
where cord-and-plug connection of a water heater is chosen as the connection
wiring method. Such specific requirements will allow cord manufacturers to
address this issue with properly rated cord insulation and connections while
also allowing manufacturers of water heater appliances to be able to allow a
connection method that is favored by both electricians and plumbers making
new installations and by plumbers and homeowners replacing such appliances.

Panel Meeting Action: Reject

Panel Statement: The submitter has not substantiated a need for an exception
to 400.8(1): ??cords shall not be used?as a substitute for fixed wiring of a
structure.? The panel notes that water heaters are often installed near other
heating equipment or in areas used for storage of tools and other implements
that can damage cords. They are infrequently replaced, have no vibration
concerns, and can be serviced in place. Cellar installation of water heaters may
also necessitate that the cord be plugged into a ceiling receptacle, requiring a
cord longer than proposed and increasing the risk of cord damage.

Number Eligible to Vote: 14
Ballot Results: Affirmative: 14

 

[Dennis Alwon]

The ground pin/prong is slightly longer on plug caps that are intended to be used on a grounded circuit. It is a function of the plug, not the receptacle. The 3-wire dryer cord does not comply.

That makes some sense but who unplugs things by pulling directly out. I bet with the angle plugs you would tend to pull down or up and work the cord cap out. This would not insure anything, i don't think. Thanks for that info tho, I never noticed it.

 

[mdshunk]

That makes some sense but who unplugs things by pulling directly out. I bet with the angle plugs you would tend to pull down or up and work the cord cap out. This would not insure anything, i don't think.

Hey, you'll have to take that up with management. I just work here.

 

[480sparky]

That makes some sense but who unplugs things by pulling directly out. I bet with the angle plugs you would tend to pull down or up and work the cord cap out. This would not insure anything, i don't think. Thanks for that info tho, I never noticed it.

I doubt with a proper ground prong on a cord, you would be able to plug in the hots and/or neutral without having the ground engaged first. You could twist it quite a bit, but you would have to straighten it out in order to get power to the hot prongs. Try it sometime. You may be able to do it, but you'll most likely damage the cord end by then.

 

[iwire]

It comes with a factory cord, I hope it is listed for it.... find one that does not come with a factory cord...

Dude, you set the terms. :grin:

You did not specify any limitations.

 

[stickboy1375]

Dude, you set the terms. :grin:

You did not specify any limitations.

I know... next time we'll sign a contract... :grin:

 

[la2151]

disconnect

disconnect

HI . I just started a remodel & went to find the water heater noticed,some one previous had used a 30 dryer plug & a 6ft dryer cord & had it pluged in..I had never been required b 4 as well to have a disconnect for water heater,, Thanks.

 

[stickboy1375]

I had never been required b 4 as well to have a disconnect for water heater,, Thanks.

Sure you have, The nec requires one...:wink:

 

[Dennis Alwon]

Sure you have, The nec requires one...:wink:

Do you remember when it was required. I remember it was not required years ago but I am not sure if there was a code change on this or if the locals all called for it. I know I didn't install discos on water heaters for years but not sure when that changed.

 

[kbsparky]

....Isn't the 3 wire dryer ground terminal grounded to the metal of the receptacle?

No, it is not.

A 3-wire "dryer" receptacle is a NEMA10-30R (non-grounding). The neutral terminal is not connected to the metal strapping of the receptacle.

For a proper connection, one should install a NEMA 6-30R which has 2 horizontal slots, and one round "groundING" hole: