OSHA defines an energy isolating device as 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.