Lock Out
The placement of a locking device on an energy isolating device. Eg. Lock & chain on an isolation valve, electrical breaker locked & open position, etc.
Tag Out
The placement of a tag on an energy isolating or lock out device, e.g. on the lock, at the blind or valve, lock at the lockout box,etc
Try Out
After all switches, valves and devices are locked out and tagged, and the equipment is cleared of personnel, attempts are then made to try starting the equipment (push button, actuators, etc.)