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ronmath

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Burnsville, MN
"Circuit breakers shall be trip free and capable of being closed and opened by manual operation"

I am having an inspector telling me that we can not install lock-on devices on circuit breakers because of this statement (other than where specifically allowed elsewhere in the code as I pointed out). My interpretation would be that the devices can be easily removed and the breaker turned off manually. Any other opionions?

Thanks,
 
Not sure why the inspector thinks this as it is clearly allowed by code. A breaker lock will still allow a breaker to trip and I don't believe a lock should be installed to keep the breaker on. I thought the lock was only on when you lock it off.
 
Dennis,

These devices are "lock-on" devices attached to the handle of the breaker by a screw. They do allow the breaker to trip normally, but do not allow the breaker to be turned off without removal of the device. They use these in retail stores alot so critical devices are not turned off accidentally. This is the first time we have not been allowed to specify these devices.
 
Dennis Alwon said:
Not sure why the inspector thinks this as it is clearly allowed by code. A breaker lock will still allow a breaker to trip and I don't believe a lock should be installed to keep the breaker on. I thought the lock was only on when you lock it off.
Click to expand...


Dennis in our neck of the woods they are required on circuits with emergency lites and exits, fire alarms etc.

Charlie
 
Well then it is clear the inspector is incorrect. I don't think I ever used a breaker lock. I assumed, you what that does :grin:, that it was a device on the breaker and no lock was attached but could be.
 
If
"capable of being closed and opened by manual operation"
then
padlocks can be removed by manual operation provided you have the combination.

His definition of "manual operation" seems to be limited to one-step manual operation; flipping the handle.
Is this a commonly accepted definition, perhaps relating to the speed at which a breaker can be manually opened or closed?

But, fer sure, locks that open on voice recognition or retinal scans are forbidden!:grin:
 
OSHA 1910.334 (b)
1910.334(b)(2)
Reclosing circuits after protective device operation. After a circuit is deenergized by a circuit protective device, the circuit may not be manually reenergized until it has been determined that the equipment and circuit can be safely energized. The repetitive manual reclosing of circuit breakers or reenergizing circuits through replaced fuses is prohibited.

Note: When it can be determined from the design of the circuit and the overcurrent devices involved that the automatic operation of a device was caused by an overload rather than a fault condition, no examination of the circuit or connected equipment is needed before the circuit is reenergized.
 
Explain that "trip free" is a manufacturing requirement specifically designed into the breaker in order to accommodate locked-on breaker handles, and not an installation requirement that the handle be free to move.
 
Dennis Alwon said:
Well then it is clear the inspector is incorrect. I don't think I ever used a breaker lock. I assumed, you what that does :grin:, that it was a device on the breaker and no lock was attached but could be.
Click to expand...

Some of them allow you to lock it in on or off position.
 
davidr43229 said:
OSHA 1910.334 (b)
1910.334(b)(2)
. . . After a circuit is deenergized by a circuit protective device, the circuit may not be manually reenergized until it has been determined that the equipment and circuit can be safely energized. The repetitive manual reclosing of circuit breakers or reenergizing circuits through replaced fuses is prohibited. . . .
Click to expand...
I like this as a rationale in favor of "Lock-Ons". A fair number of those who operate equipment, upon loosing power, will think only of getting the power back and not care to find out what caused the outage. IMO, those most likely to ignore the cause of the outage will be more likely to be thwarted in their attempts to reclose the breaker by the lowly Lock-On, because they will have to call a maintenance person to deal with the lock.

I see the Lock-On as, on average, a device that increases overall safety.
 
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