Residential wall oven disconnect

[nizak]

Recently installed a 40A 120/240 residential wall oven. Unit is supplied with a FMC whip and factory installed conductors. Only means of connecting is a J-box in cabinet above unit.

I installed a 2 pole breaker lock in the basement panel to serve as disconnecting means. When AHJ opened the cover he asked why went to the trouble of putting the locking device on it. I replied , in order for it to code compliant. He commented that he only requires disconnecting means for cooking appliances in commercial applications.
Guess I could have saved the $5 and 10 minutes.

 

[Ponchik]

422.31(B) applies to your installation. It does not distinguish between residential or commercial. You did the correct install.

 

[Cavie]

Inspector is wrong. Ask him to explain how he came up with that.

 

[John120/240]

Inspector is wrong. Ask him to explain how he came up with that.

Yes That is true. But the inspectors ruling will save the OP $5 & 10 minutes, if he follows that logic. For a clear conscience I would still install the breaker lock & not look back.

 

[roy g]

roy g

roy g

in the nec handbook (2011) in the comment it states (422.31 B) that locking devices which depend on set screw are not approved. Do all manufactures have the available in residential style breakers? I have only seen the Sq D set screw type which aren't capable of placing a lock in the opening position.

 

[Cavie]

The lock pictured is not a legal disconnect lockout. A disconnect lockout goes on the breaker and is held in place by the cover not by a screw. It is on the breaker 24/7. They are made for all current manufactured panel systems. They are made to install a padlock in the off position.The lock pictured it to lock a breaker in the on position. Think telephone system, computer ckts, emergency lights. The breaker will trip while installed.

 

[magoo5150]

Recently installed a 40A 120/240 residential wall oven. Unit is supplied with a FMC whip and factory installed conductors. Only means of connecting is a J-box in cabinet above unit.

I installed a 2 pole breaker lock in the basement panel to serve as disconnecting means. When AHJ opened the cover he asked why went to the trouble of putting the locking device on it. I replied , in order for it to code compliant. He commented that he only requires disconnecting means for cooking appliances in commercial applications.
Guess I could have saved the $5 and 10 minutes.

Don't fret about it. You did the right thing.

 

[kwired]

Yes That is true. But the inspectors ruling will save the OP $5 & 10 minutes, if he follows that logic. For a clear conscience I would still install the breaker lock & not look back.

Your first image doesn't have provisions for installing a lock, but will hold a breaker in on or off position - is most convenient as mentioned to prevent accidental turning off some "critical" circuit, yet the breaker can still trip should it be called upon to do so.

The second image is devices that accept a lock, but is not a device that remains attached to the breaker while not in use - so not in compliance with requirements of 422.31(B)

For 2 pole QO series you need either QO1PL or QO2PAF

 

[augie47]

I have a slightly different take on the requirement which is "depends"
My read is that IF the unit has a unit switch that actually disconnects the power then no additional lock out means is needed.
In my younger days, when electric ovens first hit the market , the switches did actually disconnect the power and had "off" positions. Now days with electronic controls, etc. no necessarily so.
I agree with the others that a breaker lock is probably needed and the device you show is not
such an animal.

 

[iwire]

I have a slightly different take on the requirement which is "depends"
My read is that IF the unit has a unit switch that actually disconnects the power then no additional lock out means is needed.
In my younger days, when electric ovens first hit the market , the switches did actually disconnect the power and had "off" positions. Now days with electronic controls, etc. no necessarily so.
I agree with the others that a breaker lock is probably needed and the device you show is not
such an animal.

I agree with Gus.

 

[sparkyrick]

Yes That is true. But the inspectors ruling will save the OP $5 & 10 minutes, if he follows that logic. For a clear conscience I would still install the breaker lock & not look back.

Actually, the two items you picked would not qualify for a locking device.

These would though:

For single pole breakers:

For 2/3 pole breakers:

 

[John120/240]

Yes That is true. But the inspectors ruling will save the OP $5 & 10 minutes, if he follows that logic. For a clear conscience I would still install the breaker lock & not look back.

Actually, the two items you picked would not qualify for a locking device.

These would though:

For single pole breakers:

For 2/3 pole breakers:

The ones that I pictured pass muster here for residential applications by the AHJ. I do see how those posted by Sparkyrick meet code.

 

[electricmanscott]

I usually don't like the "that's the way we've always done it" excuse. But... I've installed dozens and dozens of ovens and cooktops and have never ever put a disconnect or breaker lock and no inspector has ever called me on it. It's the way we've always done it. :slaphead:

 

[kwired]

I usually don't like the "that's the way we've always done it" excuse. But... I've installed dozens and dozens of ovens and cooktops and have never ever put a disconnect or breaker lock and no inspector has ever called me on it. It's the way we've always done it. :slaphead:

If they let you get away with it that is just the way it is I guess, but just beware someday someone may enforce it and it is hard to argue against something that has been in the code for some time.

I honestly don't know what I think of the rule, it makes sense, but I'd also guess that majority of locking devices installed never get used, especially in dwelling applications. But go to an industrial environment and even a disconnect within sight of equipment that NEC doesn't necessarily require to have lock attachment provisions gets locks installed on it all the time.