Electric and hybrid machines: high-voltage safety.
Future drivetrains place new demands on the mechanic's education
Electrification, which has really hit passenger cars, is also making its way into agricultural and contractor machinery: electric-driven skid steers, hybrid excavators and battery-driven tools for smaller tasks. These machines contain a high-voltage system that is fundamentally different to work with than the classic 12/24-volt electrical system you know from the diesel engine.
§Why high voltage is a different category
While the traditional low-voltage system is rarely life-threatening to touch, a high-voltage battery in an electric or hybrid vehicle can deliver power at voltages that can be fatal upon direct contact. The components are therefore marked with orange cables and warning labels, and access to them is typically locked behind panels that may only be opened by persons with the appropriate training.
§Requirements for education and certification
In the same way that the EV and hybrid car industry requires a certification course before a mechanic can work on high-voltage systems, development points toward similar requirements for heavy electric and hybrid machines. The courses combine theory about high voltage with practical training in making a system de-energized, using correct safety equipment, and handling emergencies. Without this certification, you cannot open or work directly on high-voltage parts.
- 01Know and respect the marking: orange cables mean high voltage.
- 02Always make the system de-energised according to the manufacturer's documented procedure before working on it.
- 03Use insulated gloves and tools approved for the current voltage level (e.g. according to EN60900 standard).
- 04Know the emergency procedure if a colleague comes into contact with a live part.
§Safety for the uncertified mechanic
If you are not yourself certified for high voltage, your most important task is to be able to recognise the system and leave it alone. All work on motor, hydraulic or mechanics that does not require access behind the high voltage panels can be carried out as on an ordinary machine — but be aware that some components that would otherwise be harmless on a diesel machine may be close to high voltage cables.
| Situation | What you do |
|---|---|
| Orange cable or warning sign visible | Don't touch it — call a certified colleague |
| Battery pack damaged after accident | Cordon off the area and follow the manufacturer's emergency procedure |
| Common mechanical work on an electric/hybrid machine | Performed as normal but keep distance from high-voltage components. |
| Uncertain whether a system is de-energized | Always assume it is live until the opposite is confirmed |
Electric and hybrid technology in heavy machinery is still in its early stages, but it is growing. In the coming years, the trade will require more mechanics to take advanced training in high-voltage safety, as has already happened in the automotive industry. Knowing the principles now gives you a head start when your workplace gets its first electric or hybrid machine.