Breakers "Locked in ON" position

[baxter4]

Does anyone know if a typical 20 amp breaker will properly trip in an overloaded condition if it has been locked in the ON position? We have installed a new fire alarm system in our facility and the EC finished off the job by installing what I commonly refer to a LOTO brackets on each of the 8-10 circuits that the new hardware was wired to, this was to meet one of the fire codes--not sure which one. The EC is using this device to lock ON the breaker so that it will not accidentally be turned off. We typically use these type devices for locking the breaker in the OFF position when servicing/repairing the equipment. We were just wondering if these were code approved for this application or if they would prevent a breaker from tripping if overloaded?
This is my first post, thanks for the help.

 

[raider1]

Welcome to the forum.

New breakers are designed so the the trip funtion will work with the handle locked in the "ON" position.

Chris

 

[jeremysterling]

Welcome to the forum!

In the past, I may have tried real hard to hold a tripping breaker in the on position (e.g. one last hole to core before I can go home) but, alas, the breaker refuses to stay shut even when I try to hold it shut.

I wish the data floor hosts would lock their 20A breakers on. I've inadvertently shut off tier 4 redundant power to web servers. Oops...

I think it is OK to lock on life safety systems.

 

[480sparky]

Typically, breakers that supply fire alarms are not locked on with LOTO equipment.

It should be locked on with a manufacturers' approved method:

 

[don_resqcapt19]

Typically, breakers that supply fire alarms are not locked on with LOTO equipment.

A lot of the LOTO clips are designed so that you can lock the breaker in either the open or closed position. There is no reason not to use them that way.

Take a look at the GE THP 100 breaker lock for the same family of breakers as the THL 103. It has a little tap that can be used with a ty-rap to lock the breaker in either position. I think that you can also use a lock with the breaker handle in either position.

 

[480sparky]

A lot of the LOTO clips are designed so that you can lock the breaker in either the open or closed position. There is no reason not to use them that way.....

Some panel covers won't fit and doors won't close with LOTOs.

 

[charlie]

240.80 Method of Operation. Circuit breakers shall be trip free and capable of being closed and opened by manual operation. Their normal method of operation by other than manual means, such as electrical or pneumatic, shall be permitted if means for manual operation are also provided.

The term trip free indicates that a circuit breaker is required to open under overcurrent conditions even when the handle is held or locked in the on position. :smile:

 

[nhfire77]

NFPA 72 ? Section 4.4.1.4.2.2


Locked breaker is required. I love up selling a lock and proper marking when the EC doesn't.

Even better, the breaker is off the panel is in trouble (AC loss). (for the last 24 hours)

Batteries replaced with those locks?