Breaker locked in the closed (on) position

[memyselfandI]

I have researched this and have found no conclusive evidence so I have to ask. Is there a code reference that states that a breaker cannot be locked in the on position? This is an industrial facility we are talking about and the question was asked on whether it could be done or not. Little help on this?

 

[iwire]

To sum it up, no.

 

[chris kennedy]

It will still trip internally if need be. Common practice for F/A circuits.

 

[memyselfandI]

To sum it up, no.

"no" you can't do it or "no" there is no reference. I believe it is the former and not the latter.

 

[bphgravity]

Lokcing the breaker switch in the on position will not effect its overload / overcurrent operation, so no problem there.

The only possible consideration is in the event the breaker is serving as a required discsonnecting means that is also required to be readily accessible. In this case, the locking means may be interpreted as an obstacle that needs to be removed before it can be accessed.

Othersise, no code issue at all.

 

[iwire]

"no" you can't do it or "no" there is no reference. I believe it is the former and not the latter.

In my opinion the NEC does not prohibit locking the device on.

 

[augie47]

As far as it effecting the breakers OCP, it does not. The breaker will still trip. Beyond that, in my opinion, I think it's going to depend on what the breakers is used for and the type situation. 240.24 might be a decent guide. If it's a situation where an occupant might need to turn it off, then I'd say it should not be locked. If it falls under a situation where it only needs to be turned off by authorized personnel and it meets 240.24(B)(1) then I don't see much difference in locking the breaker and locking the enclosure {see also 110.26(G)}
If it is a disconnect means for a motor or appliance (430.102, 422.30) then I don't see where you could lock it on.
It may be one of the ult imate judgement calls. I would frown in locking any breaker but if it was readily accessible to the public and feeding my life support equipment, I would proably lock it.
In you indutrial facility with maintenance personnel, I see no problem.

 

[iwire]

As far as it effecting the breakers OCP, it does not. The breaker will still trip. Beyond that, in my opinion, I think it's going to depend on what the breakers is used for and the type situation. 240.24 might be a decent guide. If it's a situation where an occupant might need to turn it off, then I'd say it should not be locked. If it falls under a situation where it only needs to be turned off by authprized personnel and it meets 240.24(B)(1) then I don't see much difference in locking the breaker and locking the enclosure {see also 110.26(G)}
If it is a disconnect means for a motor or applinace (430.102, 422.30) then I don't see where you could lock it on.

IMO none of the disconnecting means you describe are intended to be 'emergency stops'. They are there for servicing the equipment and all can be locked on or be in a locked room.

 

[infinity]

Breaker "on" locks are required in Article 700 of the NEC:

700.12(F) Unit Equipment. Individual unit equipment for emergency illumination shall consist of the following:
(1) A rechargeable battery
(2) A battery charging means
(3) Provisions for one or more lamps mounted on the equipment, or shall be permitted to have terminals for remote lamps, or both
(4) A relaying device arranged to energize the lamps automatically upon failure of the supply to the unit equipment
The batteries shall be of suitable rating and capacity to supply and maintain at not less than 87? percent of the nominal battery voltage for the total lamp load associated with the unit for a period of at least 1? hours, or the unit equipment shall supply and maintain not less than 60 percent of the initial emergency illumination for a period of at least 1? hours. Storage batteries, whether of the acid or alkali type, shall be designed and constructed to meet the requirements of emergency service.
Unit equipment shall be permanently fixed in place (i.e., not portable) and shall have all wiring to each unit installed in accordance with the requirements of any of the wiring methods in Chapter 3. Flexible cord-and-plug connection shall be permitted, provided that the cord does not exceed 900 mm (3 ft) in length. The branch circuit feeding the unit equipment shall be the same branch circuit as that serving the normal lighting in the area and connected ahead of any local switches. The branch circuit that feeds unit equipment shall be clearly identified at the distribution panel. Emergency luminaires that obtain power from a unit equipment and are not part of the unit equipment shall be wired to the unit equipment as required by 700.9 and by one of the wiring methods of Chapter 3.
Exception: In a separate and uninterrupted area supplied by a minimum of three normal lighting circuits, a separate branch circuit for unit equipment shall be permitted if it originates from the same panelboard as that of the normal lighting circuits and is provided with a lock-on feature.

 

[cpal]

I see it done all the time.

The BC that alerts the EMG GEN is locked in the on posistion. All of these breakers have an internal trip free feature it does not compromise the ability of the ocpd to function. It does require a individual with a screw driver to reset.

If this was installed on a circuit the requires LOTO (in the op) then I woud require a down stream lockable disconnect, or other suitable device.

 

[mcclary's electrical]

IMO none of the disconnecting means you describe are intended to be 'emergency stops'. They are there for servicing the equipment and all can be locked on or be in a locked room.

I agree, and that 's how I compare it in my mind. His locked breaker is no different than a locked electrical room full of closed breaker.

 

[Jim W in Tampa]

"no" you can't do it or "no" there is no reference. I believe it is the former and not the latter.

Why do you think it can't be done ? There are some circuits we simply do not want accidently turned off. Nothing in nec to say we can't and as mentioned it still will trip.

 

[acrwc10]

Why do you think it can't be done ? There are some circuits we simply do not want accidently turned off. Nothing in nec to say we can't and as mentioned it still will trip.

That sums it up.. every new house we do out here (CA) has a fire sprinkler system and the alarm/ monitoring system that gets connected to it requires a lock to keep it from getting shut off.