Disconnect for fastened in place Hot Water Heaters

[KTK]

According to Mike's diagram "Figure 422-7" using a 30A plug and a Dryer Pigtail is not allowed anymore? It seems that 422.16. A 1 & 2 says that we can if "the appliance is intended or identified for flexible cord connection." It seems like there is NOT agreement here between Mike Holt and the NEC? Please clarify. Kitk T.

 

[hillbilly1]

Dryer pigtail would be incorrect anyway since most water heaters are straight 208/240.

 

[augie47]

UL listing (KSDT) on household storage water hesters states:
These water heaters are intended for household use and permanent connection to the supply source in accordance with ANSI/NFPA 70, ‘‘NationalElectrical Code.’’
Art 422 does allow for the use of a "breaker lock"in lieu of a disconnect

 

[KTK]

And why couldn't a 4-wire dryer plug and pigtail be used as a "disconnect" if the HWH was approved for "flexible cor connection" as per 422. A 1 & 2 and 422.13 --> if the amperage is 24 Amps or less?

 

[texie]

And why couldn't a 4-wire dryer plug and pigtail be used as a "disconnect" if the HWH was approved for "flexible cor connection" as per 422. A 1 & 2 and 422.13 --> if the amperage is 24 Amps or less?

You can't use a cord and plug as for the reason augie47 stated. Even if cord and plug was allowed you could not use a 4 wire or even a 3 wire "dryer" cord. It would need to be a NEMA 6-30.

 

[LarryFine]

I once wired a house that was so nice, I didn't want to install a typical disco for the water heater, so I used a 30a 2p toggle switch.

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[Fred B]

Sorry, excuse me, but I'm totally unaware or even heard of such as an issue before. Always just turn off breaker for a wated heater. Is there something I've missed that requires something in addition to the breaker to shut off and disconnect a WH? Please educate me, code references too please so that I can share the info.
Also, if never heard of such a thing as wiring a water heater with a plug. The only ones I've come across are single pole 120V plug in.

 

[LarryFine]

Is there something I've missed that requires something in addition to the breaker to shut off and disconnect a WH?

Perfectly okay if within sight and 50 feet; usually dependent on being in the same room.

 

[KTK]

The disconnect (usually next to the HWH) is to make it easier for the plumber or Home owner to change out the HWH tank. So, you are saying a disconnect is no longer required near the HWH?

 

[rnatalie]

The disconnect was never required to be "near" the HWH. It needs to either be "within sight of" it or able to be locked in the open position.

 

[Fred B]

The disconnect was never required to be "near" the HWH. It needs to either be "within sight of" it or able to be locked in the open position.

Does a LOTO device count or does the breaker have to have the permanent device installed on the breaker?

 

[LarryFine]

The idea is that someone cant unwittingly re-energize the circuit until the service person has finished.

 

[tom baker]

Does a LOTO device count or does the breaker have to have the permanent device installed on the breaker?

See 110.25 for requirements for lockable disconnecting means. For water heaters, there has long been a requirement for a lock out on the disconnecting means if its not in sight.
Note this requirement does not apply to hot water heaters. No need to heat hot water.

 

[hbiss]

Seems to me that a cord and plug connection for a furnace or boiler shouldn't be allowed either since it's fastened in place.

-Hal

 

[texie]

Seems to me that a cord and plug connection for a furnace or boiler shouldn't be allowed either since it's fastened in place.

-Hal

It's not. See 422.16.