High-Voltage Electrical Safety Practices and PPE
What high voltage means
In xEV service, high voltage is any circuit above 60 V DC or 30 V AC RMS. Traction packs commonly run 200–400 V, and 800 V architectures are increasingly common, so treat every HV circuit as lethal. Body resistance drops with moisture, sweat, or cuts; roughly 1 mA is perceptible, 10–16 mA can cause a "let-go" failure, and about 50 mA across the heart can be fatal.
Required PPE and habits
- Class 0 rubber insulating gloves rated 1000 V AC / 1500 V DC, worn with leather protectors. Dielectric-test every 6 months, air-test before each use, and inspect for cuts, ozone cracking, and contamination.
- Insulated tools rated 1000 V, a CAT III or CAT IV meter and leads rated for the system voltage, face shield, and arc-rated clothing per the employer's risk assessment.
- Remove jewelry and watches, tie back long hair, and work single-handed where practical.
Traps that show up in questions
Wearing rubber gloves without leather protectors; relying on a visual check instead of an air test; using a CAT II meter or damaged leads; assuming a 12 V disconnect de-energizes the pack; and assuming every HV cable is orange-some manufacturers use blue or yellow, so read labels, not colors.
Rule of thumb: prove–test–prove
Before touching a conductor, verify the meter on a known live source, test the conductor, then re-verify the meter. A meter that fails to read zero may be broken, not proof of a dead circuit.