High-Voltage Safety Practices and Personal Protective Equipment
The hazard, not the label
High-voltage traction systems in light-duty EVs typically run 200–800 V DC, far above the 60 V DC / 30 V AC threshold most standards use to define "high voltage." The hazard is not only shock: a fault can produce arc flash, thermal burns, and blast, and a damaged lithium pack can vent flammable gas. Treat every orange cable as energized until a meter proves otherwise.
PPE and test equipment
Rubber insulating gloves must match the system voltage - Class 00 is rated 1000 V AC / 750 V DC and Class 0 is rated 1000 V AC / 1500 V DC - and must be air-tested before each use and electrically retested on the required interval (commonly six months). Leather protectors go over the rubber, never instead of it. Use a CAT III meter rated at or above the system voltage with fused leads, plus an insulation tester for isolation checks. Remove jewelry and watches, and use a one-hand technique where practical.
Traps candidates fall for
Expired or untested gloves; a CAT II "automotive" meter on a 400 V bus; assuming the car is dead because it is silent; assuming a 12 V disconnect kills HV; reaching into a connector to feel for a latch. Another trap: confusing a 48 V mild-hybrid system, which is not HV PPE work, with a full traction system.
Rule of thumb
Isolation is judged per volt of working voltage: many standards require at least 100 Ω/V, and most OEMs specify 500 Ω/V. For a 400 V pack that is a 200 kΩ minimum.
Worked example: a 400 V nominal pack measures 45 MΩ on an insulation tester. The OEM minimum is 200 kΩ, so it passes with a wide margin.