Problem with lockouts and safety

[patrussell]

We have a 4 day outage starting tomorrow and were planning to lock out all electrical equipment to allow for motor testing and various mechanical work. One of my electricians has asked about a situation that I do not have a good solution for and need some help.

In locking out the motors I need to isolate them at the MCC which has external handles that operate the internal breaker. If I lock the handles I cannot open the door to connect the test equipment. I can lock out all the disconnects and have the doors left ajar but then the incoming 480V is exposed.

Any thoughts on my best course of action?

Pat Russell

 

[waross]

Lock out the disconnects with the doors ajar. Post warning signs.
Emphasize at the pre-shutdown safety meeting that there are exposed parts in the MCCs.
Ban all but competent workers from the MCC room.
It is within the normal duties of an industrial electrician to work on an open MCC unit with the switch off and the door open. There are few exposed energised parts in an MCC unit when the switch is off, and in most designs there are no exposed current carrying parts with the switch off.
Alternately you may lock off the supply to the MCCs.
respectfully

 

[patrussell]

Thanks for the reply.

My initial thoughts were the same as you laid out but I ended up speaking with my safety department and they would not let me leave the doors opened. Looks like we'll have to work with one motor at a time.


Pat Russell

 

[waross]

Do your MCCs have exposed energised parts with the doors open and the switches off?
What make and age are they?
I understand if your shutdown keeps you too busy to respond for a week or so.
respectfully