Does this qualify as a lockout?

[jischr]

We have equipment on the floor that has a 120V heater control circuit switch. When thrown the switch starts a screw motor in the MCC bucket to retract the blades and isolate the 480V circuit thereby allowing work on the equipment (not the 480V circuit). An indicator light changes color when the process is complete. I'm not sure if it is fed from the 480V system or a contact from the screw system. For the sake of this discussion let's presume the 480V switch can not be manually closed in the MCC room when the screw motor has retracted the blades. The MCC is located on a different floor of the buiding and not 'convienient' to access. The current practice is to lockout the 120V control circuit switch at the machine.
The question is, does this meet 1910.147 requirements of energy isolation. My view is no it does not because the 120V switch is not an energy isolation device for the 480V circuit. Others state it provides equivalent protection.
Thoughts? Comments?

 

[Dennis Alwon]

The question is, does this meet 1910.147 requirements of energy isolation.

I believe it may help if you explained what this req. is or pertains to.

 

[jischr]

OSHA 1910.147 Control of Hazardous Energy requires an energy isolation device be locked out to prevent unanticipated energization of an energy source. It defines an energy isolation device as -
Energy isolating device. A mechanical device that physically prevents the transmission or release of energy, including but not limited to the following: A manually operated electrical circuit breaker; a disconnect switch; a manually operated switch by which the conductors of a circuit can be disconnected from all ungrounded supply conductors, and, in addition, no pole can be operated independently; a line valve; a block; and any similar device used to block or isolate energy. Push buttons, selector switches and other control circuit type devices are not energy isolating devices.

To me, the 120V switch is a control circuit device and does not meet the definition of a energy isolating device. Therefore the requirements 1910.147 and 1910.333 Selection and Use of Work Practices (electrical) are not being met.

 

[GoldDigger]

I believe it may help if you explained what this req. is or pertains to.

See http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9804&p_table=STANDARDS from OSHA CFR 1910 on LOTO requirements for working on machinery. Not the electrical safety side but the unintentional machine operation side.
It also covers stored energy inside the machine (like the preloaded tension springs on a garage door, which can do major damage if you handle them wrong.)

 

[WorkSafe]

Forgive my ignorance, but is the screw motor in the MCC bucket still "energized" after the switch is thrown? If so, then this would not comply with the intent of LO/TO.