Energy Isolating Device (EID)

Energy isolating device (EID): A mechanical device that physically prevents transmission or release of energy. The OSHA lockout/tagout standard requires authorized employees to apply their locks to an EID prior to starting work. EIDs protect against the unexpected reenergization of equipment.

Examples:

• Electrical circuit breaker
• Electrical disconnect switch
• Hydraulic valve
• Pneumatic valve
• Pipeline valve
• Slide gate
• Machine block
• Block
• Blind flange
• Other devices that positively block or isolate energy.

Pushbuttons, selector switches, and other control circuit devices are NOT energy isolation devices. They only isolate one, not all, of the conductors providing power to the equipment.

An authorized employee must identify all energy isolation devices associated with the equipment being worked on. This information is typically available on the machine-specific written lockout/tagout procedure forms.

All other employees must NEVER try to activate an EID that has a lock or tag on it or ever remove someone else’s lock or tag. Those devices are protecting someone’s life.