Even after applying locks and tags, you must test equipment to confirm it is de-energized before working on it. This is a critical OSHA requirement under 1910.333(b)(2)(iv) and 1926.417.
Why It Matters:
Assuming equipment is de-energized without verification has led to serious injuries and deaths. Voltage can remain due to wiring errors, residual charge in capacitors, or failure to isolate all sources.
Key Points:
- Use a properly rated voltage tester to check for the presence of voltage before starting any work.
- Always test the tester on a known live source first, then test the circuit, then re-test the tester — this is called the “Live-Dead-Live” method.
- Wear appropriate PPE during testing in case voltage is still present.
- Only qualified persons should perform this testing under OSHA’s electrical safety standards.
- Never let pressure or deadlines cause you to skip this step.
✅ If you don’t test, you don’t know — and guessing isn’t safe.
Ask the Crew:
- Who is verifying zero energy before we begin?
- Are our testers rated and working properly?