Basic safety tips for servicing hybrids

There are new dangers that hybrid vehicles can bring to the service technician, says Peter Zaidel, a product manager with KPA, the nationwide leader in environmental and safety compliance programs for vehicle and equipment dealers ( Fortunately, manufacturers designed hybrid vehicles not only with an eye on fuel efficiency, but also with strong consideration for the safety of service technicians.

He offers some key safety basics to share with service technicians:

1. How to identify a vehicle as a hybrid.

Almost all hybrids share these common identifiers. One is hybrid badging on the body of the vehicle, typically the rear right section and under-hood identifiers, including the extra motor and the inverter. Another is the "Ready" indicator inside the vehicle in the ignition area. There is also orange high-voltage power cables.

2. How to determine if the vehicle is really turned off.

"This may be the single most important safety factor for service technicians working in a shop where there are hybrid vehicles because the hybrid system is silent when running on battery," points out Zaidel. "Hybrid systems can automatically turn themselves off and on, switching between the high-voltage battery and the gasoline engine, so it is easy for the technician to be unpleasantly surprised that a vehicle thought to be 'off' is in fact 'on.'"

He recommends observing these service protocols:

  • A hybrid is not necessarily powered off until it is verified that the vehicle is powered down.
  • Keep vehicle keys a safe distance from the hybrid - more than 20' - as many hybrids have a keyless ignition, with on/off sensitivity up to 20' away from the vehicle.
  • Always check the vehicle dashboard hybrid indicator to ensure the vehicle is truly "off" before any kind of work is performed on the vehicle.

3. How to protect one's self from high voltage.

While the amount of voltage and amperage in hybrid vehicles is enough to be fatal if a technician comes in contact with the high-voltage circuits, the high-voltage system does not ground to the body or the chassis, but rather is isolated from the vehicle body completely, Zaidel points out. A technician would have to touch pole-to-pole or become part of the circuit for an injury to occur.

As a highly visible safety warning, all high-voltage circuits are encased and heavily insulated, and normally identified by the SAE standard color-coding of bright orange.

Never cut into, touch, mangle or otherwise disturb the big orange cables that carry the high voltage from the batteries (in the back) to the controller (in the front), he warns. Always wear class "O" heavy-duty gloves (lineman's gloves) rated to withstand 1,000 volts when disconnecting high-voltage components, such as the battery.

These gloves should be maintained in excellent condition and checked prior to each use to ensure there are no leaks, he says. Even a small opening can draw current that is seeking a ground.

Always disconnect the high-voltage hybrid battery before doing any major repair work or electrical work, he recommends. Most manufacturers also recommend waiting at least 10 minutes before working on the vehicle after the battery has been isolated or disconnected. The high-voltage capacitors need time to discharge so there is no residual voltage to pose a shock hazard.

"Hybrid vehicles may seem similar to gasoline-powered engines, and indeed there is much in common," concludes Zaidel. "But the differences are important ones from a safety perspective, bringing risks of injury and even death to the untrained or careless service technician.

"Proper training, adherence to a company's service operations protocols and constant vigilance around these 'silent while on' vehicles will ensure a safe environment."