Recommendations for common Safety Rules for Working on Electric Vehicle (HEV) and Hybrid Electric Vehicles (PHEV).
Technicians need to be aware of the additional hazards that exist when working with these vehicles. E&HVs introduce additional hazards into the workplace to those normally associated with the repair and maintenance of vehicles. Voltages present in E&HVs can be up to 650 Volts direct current (dc). Accidental contact with parts that are live can be fatal.
There are substantial differences in the designs of E&HVs from different manufacturers. Having information specific to the manufacturer and the vehicle being worked on is important in identifying what actions are necessary to work safely.
Risks of working with E & HV's
- Fatal electric shock.
- The storage of electrical energy with the potential to cause explosion or fire.
- Components that may retain a dangerous voltage even when a vehicle is switched off.
- Electric motors or the vehicle itself that may move unexpectedly due to magnetic forces within the motors.
- Manual handling risks associated with battery replacement.
- The potential for the release of explosive gases and harmful liquids if batteries are damaged or incorrectly modified.
- The potential for the electrical systems on the vehicle to affect medical devices such as pacemakers.
- Remote operation keys that only need to be close to the vehicle for the vehicle to be powered up should be kept away from vehicles. This is to prevent the vehicle from accidentally moving.
- People who move these vehicles around the workplace should be aware that others may not hear it approaching them. Similarly, people who work around E&HVs should be aware that they may move without warning.
Always locate the vehicle within an area that can be secured and barrier off such that people who could be put at risk are not able to approach the vehicle. Warning signs should be used to make people aware of the dangers. Pressure washing has the potential to damage high voltage electrical components and cables. High voltage cables are usually coloured orange.
Refer to guidance from manufacturers before valeting in any under body areas including the engine bay
Vehicles should be visually checked for signs of damage to high voltage electrical components or cabling (usually coloured orange). Consider whether the integrity of the battery is likely to have been compromised. Shorting or loss of coolant may present ignition sources in the event of fuel spillage. If the vehicle is damaged or faulty, and if safe to do so, isolate the high voltage battery system using the isolation device on the vehicle.
Refer to manufacturer’s instructions for guidance
During any recovery onto a recovery vehicle, the remote operation key should be removed to a suitable distance and the standard 12/24v battery disconnected to prevent the vehicle from being activated/started.
Remote operation keys should always be kept away from the vehicle to prevent any accidental operation of electrical systems and accidental movement of the vehicle. Keys should be locked away with access controlled by the person working on the vehicle. If the key is required during the work the person working on the vehicle should check that the vehicle is in a safe condition before the key is retrieved.
Have access to reliable sources of information for specific vehicle types.
Avoid towing E&HV vehicles unless it can be determined that it is safe to do so. Dangerous voltages can be generated by movement of the drive wheels.
Unless a specific task requires the vehicle to be energised always isolate or disconnect the high voltage battery in accordance with manufacturer’s instructions.
Determine the locations of high voltage cables before carrying out tasks such as panel replacement, cutting or welding. Take appropriate precautions to prevent them from being damaged.
High voltage systems should be isolated (that is the power disconnected and secured such that it cannot be inadvertently switched back on) and proven dead by testing before any work is undertaken. Always isolate and lock off the source of electricity and in accordance with manufacturer’s instructions. You must always test and prove that any high voltage cable or electrical component is dead prior to carrying out any work on it.
Even when isolated, vehicle batteries and other components may still contain large amounts of energy and retain a high voltage. Only suitable tools and test equipment should be used. These may include electrically insulated tools and test equipment.
Some electronic components may store dangerous amounts of electricity even when the vehicle is off and the battery isolated. Refer to manufacturers data on how to discharge stored energy.
There may be circumstances (after collision damage) where it has not been possible to fully isolate the high voltage electrical systems and to discharge the stored energy in the system. Refer to the manufacturer’s instructions about what controls measures should be implemented before attempting to carry out further remedial work.
Battery packs are susceptible to high temperatures. The vehicle will typically be labelled advising of its maximum temperature and this should be considered when carrying operations such as painting where booth temperatures may exceed this limit. Measures should be implemented to alleviate any potential risks, such as removing the batteries or by providing insulation to limit any temperature increase in the batteries.
Working on live electrical equipment should only be considered when there is no other way for work to be undertaken. Even then it should only be considered if it is both reasonable and safe to do so. You should consider the risks for working on this live equipment and implement suitable precautions including, as a final measure, the use of personal protective equipment (PPE). Refer to manufacturer’s instructions for precautions when working live, including their PPE requirements.
Always locate the vehicle within an area that can be secured and barrier off such that people who could be put at risk are not able to approach the vehicle. Warning signs should be used to make people aware of the dangers.
Safety Rules for use when interacting with HEV High Voltage (HV) systems
- It is a recommendation that all technicians and/or emergency service professionals are trained in safe working of Hybrid and Electric vehicles (manufacturer or recognised institution / Awarding Body certificated).
- All HEV’s to be clearly identified with warning signs and cordoned off whilst work is being undertaken on the HV system.
- Keys are removed and stored in lockable container away from the vehicle. Only the technician working on the HEV is to have access to the lockable container.
- Specific manufacturer data to be referred before disconnecting and connecting the HV systems.
- Manufacturer data should be referenced before working on any system on a HV Vehicle.
- Insulated tools, gloves and floor mats rated for work on voltages in excess of 650 volts should be used.
- Technicians and/or emergency service professionals should not work with HV systems if they have electrical health devices fitted. (Pacemaker).
- Vehicles that have been involved in a collision may have HV components exposed – precautions against fire and electric shock should be taken (fire extinguisher).