|Hybrid and Electric Vehicles |
During recent years the strive for greater fuel economy and lower emissions has seen a rapid increase in electric and hybrid drive vehicles being available. This, of course, means more of these vehicles are being presented to vehicle workshops for servicing and repair. The systems used on these vehicles vary in operation and complexity, but one thing they all share is the use of a high voltage DC system to power the electric traction motor(s). As a general rule, hybrid systems that have a full electric driving mode run on a higher voltage than vehicles that don’t.
|Are the Systems Hazardous to Work On? |
Working on these systems should be a low-risk operation. The systems are all safe to work on as long as the correct safety precautions are followed, and the correct tools and PPE are used. Failure to follow the correct safety precautions and relevant manufacturer’s instructions, could, however, prove fatal. Some vehicles have more than one hybrid battery pack, therefore it is vital to understand the system before commencing work. One example is the Mitsubishi Outlander PHEV, which uses three battery packs and as a consequence, there are three service plugs to isolate the battery packs. The battery pack is one source of high voltage danger, but there are also cables that run from the battery pack to the motor controller. All of the high voltage cables will be coloured orange.
|Hybrid vehicles use separate wiring systems for the rest of the vehicle wiring. Detection systems will isolate the hybrid battery pack if any voltage is detected leaking into the vehicle body, or the SRS system is deployed.|
|Insulated Gloves |
It is essential to wear the correct type of thick rubber Class 0 insulated gloves. The Sealey HVG1000VL gloves Grade 0 gloves are suitable for working on systems up to 1kV AC and have been tested in accordance with EN 60903.
|Insulating Mat |
It is essential to use a high voltage insulating mat to protect vehicle technicians from the risk of electric shock when working on electric or hybrid vehicles. The Sealey HVM17K02 Class 2 High voltage insulating floor mat has been independently tested and certified as offering safe protection up to 17kV AC and has been tested in accordance with BS EN 61111.
|Hand Tools |
As a further protection against the risk of electric shock, tools should be VDE approved (Verband der Elektrotechnik) and comply with BS EN 60900. This means they are capable of providing insulation up to 1500 volts DC. This not only prevents the user from electric shock but also prevents shorting out live components, in the event of incorrect battery pack isolation. Sealey offers a comprehensive range of tools which comply with these standards. STW802 torque wrench, AK6122 and S0756 Screwdriver sets, AK7177 Hex Key Set, AK7178 TRX-Star* Key Set, AK83452 Pliers Set, AK63171 Spanner Set, AK7940 and AK7941 Socket Sets.
|Non-Start Mode |
During servicing and maintenance of any hybrid vehicles internal combustion engine, it is vital to ensure the vehicle cannot self-start. The vehicle must be placed in non-start mode. This can be achieved by either removing the key from the ignition or, if the vehicle uses a smart key, by keeping it a safe distance away, normally a minimum distance of 10 feet. Failure to follow these precautions could result in the engine starting without warning. Similar precautions will apply for pure electric vehicles.
|Disconnecting the High Voltage System |
Isolating the battery pack is the first step to working on any hybrid, or electric vehicle high voltage system. Depending on the type of system, battery voltage ranges from 144 volts to 330 volts DC. DC voltage can become dangerous at 60 volts (as opposed to AC at 110 volts), so it is vital the manufacturer's procedure is followed to isolate the battery pack before commencing any work on any hybrid or electric vehicle system. Any component of the vehicle which has the risk of electric shock associated with it will carry a warning label. All manufacturers have a simple way to isolate the battery packs to allow for safe maintenance and repairs on the vehicle. This will be via a service switch(s) or a removable connection plug(s). It is vital the relevant manufacturer’s instructions are strictly adhered to when isolating the battery packs. Adhering to the aforementioned procedures should enable problem-free maintenance and repairs on Hybrid and electric vehicles.
|Rescue Pole |
Due to the high voltages found in hybrid vehicle systems, the risk of injury is present. In the event of an accident, the Sealey HRP45 High voltage rescue pole may be required. This is suitable for use up to 45kV AC in dry conditions, the rescue pole has been tested in accordance with EN 50508 and is supplied with instructions and a wall mounting bracket.