Live Work to Perform Lockout??

[padawan learner]

At my site, we have some manufacturing machines with a Main Disconnect that shuts off power to 5 sub components. Normally, all 5 sub components work together in production. The sub components do not have individual disconnects or circuit breakers, but are fed from finger safe 3 phse fuse holders. If the maintenance crew wants to power down one sub component but not the others, they pull the fuse holder open while it is energized to lock out. Is this considered live electrical work per 70E?

 

[GoldDigger]

At my site, we have some manufacturing machines with a Main Disconnect that shuts off power to 5 sub components. Normally, all 5 sub components work together in production. The sub components do not have individual disconnects or circuit breakers, but are fed from finger safe 3 phse fuse holders. If the maintenance crew wants to power down one sub component but not the others, they pull the fuse holder open while it is energized to lock out. Is this considered live electrical work per 70E?

Pulling an energized fuse holder by itself would be considered live work, and would need PPE, and should have an arc-flash analysis.
If the machine is actually operating and cannot be shut down otherwise, then you also have to know whether the fuse holder is rated for load breaking or not. Touch safe does not mean that it can be pulled under load.

 

[cornbread]

Pulling fuses live fuses not a good practice in my humble opinion. I've conducted several arc flash investigations and on several occasions the arc flash was caused by pulling live fuses.

 

[don_resqcapt19]

Is a "removed fuse" a OSHA approved method of "lockout"?

 

[padawan learner]

Thanks, for your help. You all have confirmed what I thought.

 

[petersonra]

Is a "removed fuse" a OSHA approved method of "lockout"?

I think there might be ways to make it one without too much trouble, but not for a typical fuseblock, although I have seen some with an attachment for running a padlock through.

I am not overjoyed with the idea of pulling the fuse while there is a load on it. I am not thrilled with the idea of pulling the fuse while it is even energized, although for smaller loads it would bother me less.

 

[GoldDigger]

I think there might be ways to make it one without too much trouble, but not for a typical fuseblock, although I have seen some with an attachment for running a padlock through.

I am not overjoyed with the idea of pulling the fuse while there is a load on it. I am not thrilled with the idea of pulling the fuse while it is even energized, although for smaller loads it would bother me less.

Just as you need to take into account mechanical failure when racking or operating a breaker or pulling a meter, there is always the chance that pulling a fuse block will trigger a mechanical failure that generates an arc fault.
It is less likely the simpler the mechanism is, but not impossible and therefore not allowed without PPE.

 

[wtucker]

Is a "removed fuse" a OSHA approved method of "lockout"?

Yes.

1910.147(c)(1) Energy control program. The employer shall establish a program consisting of energy control procedures, employee training and periodic inspections to ensure that before any employee performs any servicing or maintenance on a machine or equipment where the unexpected energizing, startup or release of stored energy could occur and cause injury, the machine or equipment shall be isolated from the energy source and rendered inoperative.

What better way to isolate the equipment from the energy source, thereby rendering it inoperative? (Removing breakers works, too.) Presumably, the fuse panel would be inaccessible to unqualified persons, and a blank would be installed in the breaker panel for the same reason...

But, like all OSHA-related questions, the best answer comes from the local area director.

 

[pfalcon]

Is a "removed fuse" a OSHA approved method of "lockout"?

Yes. ...

No.

Maybe.

Lockout procedures also have to go through risk analysis. For example, removing a fuse from a cabinet that is then locked with a proper lockout lock - yes. Unscrewing the old house fuse in the garage and then walking into the house to wire - no. Pulling a fuse in a control panel and closing the door before working on a motor - maybe.

What level of access remains after pulling the fuse? What level of training do your employees have? Is there line of sight?

 

[pfalcon]

At my site, we have some ... If the maintenance crew wants to power down one sub component but not the others, they pull the fuse holder open while it is energized to lock out. Is this considered live electrical work per 70E?

Since you have an established site, OSHA requires "a documented and established policy." The safety department should be requiring a risk analysis before signing off on such a technique. As is, it's certainly live when pulling the fuse. I wouldn't sign off. I would insist you use the main disconnect for lockout or otherwise install a proper disconnect for the necessary sub-component.

 

[jischr]

Pulling a fuse from an energized circuit is not compliant with OSHA/NFPA/IEEE standards. The only defense against the injured party?s lawyers would be if removing power from the circuit presented a greater hazard than pulling the fuse. OSHA and NFPA are clear that inconvenience or loss of production do not qualify for the ?infeasible? exemption both standards provide. So the circuit must be deenergized.

I suggest you lockout the main disconnect, remove the fuses from the blocks (and I?d take the fuses out of the enclosure), lockout the fuse blocks using lockable devices, or lockout the enclosure the fuse blocks are located in. Then you could re-energize the circuits to the remaining equipment while performing work on the other one. I'm presuming the work isn't inside the enclosure with the fuse block , in which case lockout of the main disconnect is probably your only choice since the supply side of the fuse block is still energized and if its older equipment it won't be protected against contact.

 

[Aleman]

Not a good idea to pull and insert fuses with a load on them. If this was at my work I would put every piece on it's own breaker. If you don't have room then add a small
enclosure and use din mount breakers to feed the other parts of your system. Basically same as a sub panel. The din mount breakers we use are lockable as well.