Breakers locked closed | The Building Code Forum
Aug. 25, 2025
Breakers locked closed | The Building Code Forum
There is no NEC requirement that forbids locking a breaker open or closed, as long as it will still trip.
A similar question that comes up occasionally is whether someone can put a padlock on the exterior service disconnect for the building to avoid people shutting off power to the building as a prank. The answer is that you are absolutely allowed to lock it, and if the firefighters need to shut off the power, they have all manner of tools to get that lock off quickly at their disposal.
Side note, I have had electricians attempt to use those same cute little devices as the provided means to make a disconnect lockable because it was out of sight for the equipment served. I shot them down on that because I do not think they comply with 110.25. There is no definition of "lock" or "lockable" in the NEC, but one of the definitions from Merriam-Webster is "a fastening (as for a door) operated by a key or a combination". I do not think a Philips screw complies in an objective sense, and it definitely does not meet intent - the lockable device is provided for lock-out tag-out purposes.
And that further suggests that other disconnect switches not called emergency switches in the NEC are not intended for emergency use, and that no such prohibition would apply.
No NEC violation in the photo in the OP.
Cheers, Wayne
I think your best bet would be 240.24(A) which says ". . . circuit breakers shall be readily accessible . . ." Along with the definition of readily accessible, which starts off "Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to take actions such as to use tools (other than keys) . . ."
Now you have to decide whether that definition means you just need to be able to reach the circuit breaker without using tools, or whether it is implicit that you should be able to "operate, renew, or inspect" the circuit breaker without using tools. I would favor the former interpretation, as the latter would, for example, seem to preclude using screws to hold on the panel dead front, which you need to remove in order to inspect the circuit breaker.
Cheers, Wayne 1.) not sure for computers because if you really cared you would have them on a UPS, but understand
2.) Last Time I checked the FD was not going threw a list of breakers to kill power on one when they needed to shut down power, main service simplest!
3.) depending on the facility might be refrigeration units in a doctor's office where they keep samples or a lab for that matter.
4.) The facility might shut certain circuits down at night when closed, want to make sure others stay on.
5.) Might be the CEO's wine cooler or the Keg at a club, ;>)
Pretty much doesn't matter, they don't stop the safety of the breaker tripping and they prevent the power being turned off by accident.
If the FD is worried, tell them to request a string or small chain with a screwdriver attached and someplace visible for easy reach and use.
I know little things count sometimes, but really?
A similar question that comes up occasionally is whether someone can put a padlock on the exterior service disconnect for the building to avoid people shutting off power to the building as a prank. The answer is that you are absolutely allowed to lock it, and if the firefighters need to shut off the power, they have all manner of tools to get that lock off quickly at their disposal.
Side note, I have had electricians attempt to use those same cute little devices as the provided means to make a disconnect lockable because it was out of sight for the equipment served. I shot them down on that because I do not think they comply with 110.25. There is no definition of "lock" or "lockable" in the NEC, but one of the definitions from Merriam-Webster is "a fastening (as for a door) operated by a key or a combination". I do not think a Philips screw complies in an objective sense, and it definitely does not meet intent - the lockable device is provided for lock-out tag-out purposes.
i don't see anything about locking a spa emergency switch in the NEC. So does that mean it's ok to lock it closed too?Just the use of the term "emergency" switch in the NEC suggests by itself that it should not be locked closed. Since it needs to be operable in an emergency.
And that further suggests that other disconnect switches not called emergency switches in the NEC are not intended for emergency use, and that no such prohibition would apply.
No NEC violation in the photo in the OP.
Cheers, Wayne
Suggesting's are not code.That's true. To fail the installation in the OP, you should find an NEC section that says this disconnect shall not be locked closed. Or shall be operable without tools. Or something like that.
I think your best bet would be 240.24(A) which says ". . . circuit breakers shall be readily accessible . . ." Along with the definition of readily accessible, which starts off "Capable of being reached quickly for operation, renewal, or inspections without requiring those to whom ready access is requisite to take actions such as to use tools (other than keys) . . ."
Now you have to decide whether that definition means you just need to be able to reach the circuit breaker without using tools, or whether it is implicit that you should be able to "operate, renew, or inspect" the circuit breaker without using tools. I would favor the former interpretation, as the latter would, for example, seem to preclude using screws to hold on the panel dead front, which you need to remove in order to inspect the circuit breaker.
Cheers, Wayne 1.) not sure for computers because if you really cared you would have them on a UPS, but understand
2.) Last Time I checked the FD was not going threw a list of breakers to kill power on one when they needed to shut down power, main service simplest!
3.) depending on the facility might be refrigeration units in a doctor's office where they keep samples or a lab for that matter.
4.) The facility might shut certain circuits down at night when closed, want to make sure others stay on.
5.) Might be the CEO's wine cooler or the Keg at a club, ;>)
Pretty much doesn't matter, they don't stop the safety of the breaker tripping and they prevent the power being turned off by accident.
If the FD is worried, tell them to request a string or small chain with a screwdriver attached and someplace visible for easy reach and use.
I know little things count sometimes, but really?
Breaker lockouts - Mike Holt's Forum
There is an on going discussion about lockouts on DW and Disp. Also, A/H and W/H. I for one do not agree with the use of these divices. Disconects should be required. But then, I'm not in charge of such matters. However, unless you are in an industrial plant or some other safty regulated structure with some safty geru looking over your shoulder, have any of you ever accually used a lock out?. I mean, did you install a lock while you were working on the W/H of the Dishwasher?? Do the code gods really think that anyone is going to do it in a residential setting? Why not make it safe, (I think that is the purpose of the NEC) and install disconects where needed for saftey?. My rant for today!
You are entitled to your opinion, and I won't say it is wrong. But here is how I see it:
In a residential setting, dishwashers and other stuff doesn't really get serviced that often. I think the trend is more toward if it breaks, replace it. So requiring disconnect seems like overkill since they will rarely get used.
And if someone doesn't use the breaker lockouts, that's their own fault. There is only so much every one can do to protect individuals from their own lack of safety or their own negilance.
I also think that in a residential setting, its pretty unlikely that someone else is going to come along and turn on a breaker while you are working on something. For that reason, I probably wouldn't use a breaker lock either. But if someone did turn on a breaker while I was working on something, I would consider it my own fault, or the fault of the person who turned on the breaker. I wouldn't blame someone else for not installing a disconnect.
And disconnects are not always safer. My disposal has a switch (disconnect) under the cabinet. One day I stuck my hand in the disposal to get something out. The switch was about 6" from my leg, and well within sight. But I didn't see my 3 year old quietly walk up and flip on the switch. (Since then, I close the cabinet door before sticking my hand in the disposal).
But my point is, a turned off breaker would have been much safer in that particular case.
Steve
And a pad locked one even safer.Just be happy you kept your fingers. This is a significant change in 05 NEC and it has not received the attention it should the disconnects are required regardless of occupancy type
422.30 General. A means shall be provided to disconnect
each appliance from all ungrounded conductors in accordance
with the following sections of Part III. If an appliance
is supplied by more than one source, the disconnecting
means shall be grouped and identified.
422.31 Disconnection of Permanently Connected Appliances.
(A) Rated at Not Over 300 Volt-Amperes or 1⁄8 Horsepower.
For permanently connected appliances rated at not
over 300 volt-amperes or 1⁄8 hp, the branch-circuit overcurrent
device shall be permitted to serve as the disconnecting
means.
(B) Appliances Rated Over 300 Volt-Amperes or 1⁄8
Horsepower. For permanently connected appliances rated
over 300 volt-amperes or 1⁄8 hp, 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.
Note that if breaker locks are intended to satisfy this requiremnt, the means to lock must be in place at all times.
Here hard wired d/w or disposal have to have a breaker lock out on the final if there is no disc. for it.I`ve seen this lock out issue flipped back and forth here for along time.Our AHJ made it very simple.A hard wired d/w,disp.,cook top ,wall oven ,or an a/c unit where the disc. falls behind but above the unit and a w/h without a disc. not within sight of the panel will require a lock out since if it is locked out then it is not energized.All this well the service tech will check for power at the unit.The service tech won`t use them ,is a useless conversation.As long as we supply the lock out for the final inspection , we have covered our responsibility as far as the code goes.It is not up to us to provide a uniform lock out system so the service tech won`t have to have several types of locks for the lock outs.That`s a ridiculous theory.A good service electrician has almost anything on his truck to do the job they are sent on.I know one guy , his truck is a disaster area but he has at least 1 of everything ever made.
I really like the c/h lock outs that have to be flipped over so the breaker can be locked out.No actual locking mechinisim,looks like a mini madison strap with bent edges.To lock out the breaker you have to remove the panel cover and remove them after turning the breaker off,reinstall them and reinstall the cover.Our AHJ questioned them but I showed him the package that had the UL approval stamp on it.He shrugged his shoulders and signed the inspection off. You can say that they are ridiculous to install in a residential setting.You can say that they will not ever be used in a residential setting.But our inspectors require them if #1 the D/W or DISP is hard wired.#2 a cook top or wall oven need one.#3 an A/C unit or A/H/U where the pull out has its working space encroached.#4 a W/H is not within sight of the panel and has no disc.
The actual usage of the lock out is a moot subject.We install them and if the service person decides to use them ,its all well and good.As an inspector told me.If they don`t use them it`s on there tab not ours or his so install them and be legally the one that did there part.Bottom line is we install them and pass.Don`t install them and don`t pass.
In a residential setting, dishwashers and other stuff doesn't really get serviced that often. I think the trend is more toward if it breaks, replace it. So requiring disconnect seems like overkill since they will rarely get used.
And if someone doesn't use the breaker lockouts, that's their own fault. There is only so much every one can do to protect individuals from their own lack of safety or their own negilance.
I also think that in a residential setting, its pretty unlikely that someone else is going to come along and turn on a breaker while you are working on something. For that reason, I probably wouldn't use a breaker lock either. But if someone did turn on a breaker while I was working on something, I would consider it my own fault, or the fault of the person who turned on the breaker. I wouldn't blame someone else for not installing a disconnect.
And disconnects are not always safer. My disposal has a switch (disconnect) under the cabinet. One day I stuck my hand in the disposal to get something out. The switch was about 6" from my leg, and well within sight. But I didn't see my 3 year old quietly walk up and flip on the switch. (Since then, I close the cabinet door before sticking my hand in the disposal).
But my point is, a turned off breaker would have been much safer in that particular case.
Steve
steve066 said: You are entitled to your opinion, and I won't say it is wrong. But here is how I see it:
In a residential setting, dishwashers and other stuff doesn't really get serviced that often. I think the trend is more toward if it breaks, replace it. So requiring disconnect seems like overkill since they will rarely get used.
And if someone doesn't use the breaker lockouts, that's their own fault. There is only so much every one can do to protect individuals from their own lack of safety or their own negilance.
I also think that in a residential setting, its pretty unlikely that someone else is going to come along and turn on a breaker while you are working on something. For that reason, I probably wouldn't use a breaker lock either. But if someone did turn on a breaker while I was working on something, I would consider it my own fault, or the fault of the person who turned on the breaker. I wouldn't blame someone else for not installing a disconnect.
And disconnects are not always safer. My disposal has a switch (disconnect) under the cabinet. One day I stuck my hand in the disposal to get something out. The switch was about 6" from my leg, and well within sight. But I didn't see my 3 year old quietly walk up and flip on the switch. (Since then, I close the cabinet door before sticking my hand in the disposal).
But my point is, a turned off breaker would have been much safer in that particular case.
Steve
And a pad locked one even safer.Just be happy you kept your fingers. This is a significant change in 05 NEC and it has not received the attention it should the disconnects are required regardless of occupancy type
422.30 General. A means shall be provided to disconnect
each appliance from all ungrounded conductors in accordance
with the following sections of Part III. If an appliance
is supplied by more than one source, the disconnecting
means shall be grouped and identified.
422.31 Disconnection of Permanently Connected Appliances.
(A) Rated at Not Over 300 Volt-Amperes or 1⁄8 Horsepower.
For permanently connected appliances rated at not
over 300 volt-amperes or 1⁄8 hp, the branch-circuit overcurrent
device shall be permitted to serve as the disconnecting
means.
(B) Appliances Rated Over 300 Volt-Amperes or 1⁄8
Horsepower. For permanently connected appliances rated
over 300 volt-amperes or 1⁄8 hp, 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.
Note that if breaker locks are intended to satisfy this requiremnt, the means to lock must be in place at all times.
cpal said: Bryan
point well taken but,
The proposal that the means to lock the breaker (if it is to serve as a disconnect) is in 422.31, 430.102, and 440.14 (as you are probably aware) , The proposal cited the issue of service people carrying breaker locks for a wide varity of breaker manufactures. If the means to lock a breaker open (when used) is permanently present then the service person would only need to carry afew different sized locks.
Here hard wired d/w or disposal have to have a breaker lock out on the final if there is no disc. for it.I`ve seen this lock out issue flipped back and forth here for along time.Our AHJ made it very simple.A hard wired d/w,disp.,cook top ,wall oven ,or an a/c unit where the disc. falls behind but above the unit and a w/h without a disc. not within sight of the panel will require a lock out since if it is locked out then it is not energized.All this well the service tech will check for power at the unit.The service tech won`t use them ,is a useless conversation.As long as we supply the lock out for the final inspection , we have covered our responsibility as far as the code goes.It is not up to us to provide a uniform lock out system so the service tech won`t have to have several types of locks for the lock outs.That`s a ridiculous theory.A good service electrician has almost anything on his truck to do the job they are sent on.I know one guy , his truck is a disaster area but he has at least 1 of everything ever made.
I really like the c/h lock outs that have to be flipped over so the breaker can be locked out.No actual locking mechinisim,looks like a mini madison strap with bent edges.To lock out the breaker you have to remove the panel cover and remove them after turning the breaker off,reinstall them and reinstall the cover.Our AHJ questioned them but I showed him the package that had the UL approval stamp on it.He shrugged his shoulders and signed the inspection off. You can say that they are ridiculous to install in a residential setting.You can say that they will not ever be used in a residential setting.But our inspectors require them if #1 the D/W or DISP is hard wired.#2 a cook top or wall oven need one.#3 an A/C unit or A/H/U where the pull out has its working space encroached.#4 a W/H is not within sight of the panel and has no disc.
The actual usage of the lock out is a moot subject.We install them and if the service person decides to use them ,its all well and good.As an inspector told me.If they don`t use them it`s on there tab not ours or his so install them and be legally the one that did there part.Bottom line is we install them and pass.Don`t install them and don`t pass.
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