POOR HAZARDOUS ELECTRICAL ENERGY CONTROL PRACTICES

What are the examples of poor hazardous energy control practices.

The following items discuss some practices that were used in the past for safety control. These practices are not truly safe practices and should not be used today.

a) Locking out a push-button, control switch, or other pilot device does not ensure that the circuit will remain de-energized. A short circuit or ground in the control circuit can bypass the pilot device.

Another employee might even engage the contactor or starter by hand. Unless the disconnecting means is opened and locked out, an employee should not place himself in a position where unexpected equipment startup or energization might cause injury.

b) Turning the handle of a disconnect switch to the "off' position does not ensure safety. The switch linkage might be broken, leaving the switchblades engaged.

Switchblades in the open position should be confirmed by visual inspection. The load side of the switch should also be checked with a voltage tester to ensure that the outgoing circuit is de-energized, and that there is no backfeed.

c) Removing and tagging fuses does not constitute a lockout/tagout. A lockout/tagout device should be attached to the fuse clips in a manner such that no fuses can be inserted without removing the device.

If fuses are contained in a drawout fuse block,  the tag should be attached to the fuse panel, not to the drawout block. Special precautions shall be taken to prevent shock whenever energized fuse clips that are accessible to the touch must be tagged.

d) Simply opening a power circuit breaker does not ensure safety. Even if the control fuses are removed, the breaker can still be engaged with the manual operating mechanism.

The switchgear must be racked away from the bus contacts and into the "fully disconnected" position, and the racking mechanism shall be locked and tagged.