Glossary · Safe work, maintenance and competence
Tryout (lockout/tagout)
Also known as: tryout, try-out, verification of isolation
In lockout/tagout, tryout is the verification step in which controls are operated or tested to confirm that energy isolation is effective before work begins. After the tryout, controls are returned to the off or neutral position.
- Machine safety
- USA
- Maintenance
In one sentence
Tryout is the lockout/tagout step that proves isolation works, by trying to start the machine and testing for energy before work begins.
Example
After locking out a conveyor, the technician presses the local start button, checks the motor terminals with a voltage tester and confirms the pneumatic gauge reads zero before reaching into the drive.
How it applies
- USA: 29 CFR 1910.147 requires the authorized employee to verify isolation and de-energization before starting work on locked-out equipment. “Tryout” is the common industry name for this step.
- Machine safety: Tryout catches wrong isolation points, back-feeds and stored energy that was not released. Make sure nobody is exposed when the start control is operated.
- Technical documentation: Procedures state how to verify each energy type: which control to operate, which gauge to read, which measuring device to use. Remind users to return controls to off afterward.
- Evidence: In the procedure, tryout is the recorded verification that the zero-energy state was reached.
Tryout vs. zero-energy state
The zero-energy state is the condition to be reached. Tryout is the check that confirms it.