Mechanical risks related to the electrification of systems: motors, reducers, and transmissions*
The electrification of mechanical systems — motors, reducers, belts, transmissions — improves energy efficiency and control precision. However, it introduces or amplifies often underestimated mechanical risks: sudden movements, high instantaneous torques, localised heating, or continuous rotation even at low voltage.
A rigorous approach to mechanical safety is therefore essential for personnel protection and installation reliability.
1. Risk of entanglement and trapping
Electric motors present an immediate torque as soon as they are powered on. The risk of entanglement or trapping is therefore present even at low speed.
Good practices:
Ban all loose clothing, scarves, wide sleeves, or floating accessories that could be caught by a rotating shaft.
Tie back long hair and avoid inappropriate gloves: a glove caught by a rotating shaft can cause serious injury.
Work at a distance from moving or powered parts, especially during testing or transmission adjustments.
Adhering to these guidelines is essential to avoid often irreversible entanglement accidents.
2. Prevention of hazardous areas
Anticipation and signalling of risks are key elements of safety:
Install covers, grills, or transparent guards on all accessible moving parts (couplings, pulleys, chains, fans).
Mark out prohibited areas and restricted access areas with floor markings or safety tape.
Implement clear signage: mechanical hazard pictograms, labels "Do not intervene while operating".
Ensure complete clearance of tools, cables, and operators before starting.
Install a visible and easily accessible emergency stop button (E-Stop), compliant with ISO 13850.
These prevention devices help prevent an intervention or test from turning into an accident.
3. Fastenings, chassis, and structure
The mechanical forces induced by an electric motor are often underestimated. Insufficient fastening can cause misalignment, shaft breakage, or tipping.
Measures to apply:
Correctly size the chassis, supports, and anchors according to the maximum torque, weight, and expected vibrations.
Ensure all mechanical connections (screws, silent blocks, flanges) withstand the system's dynamic forces.
Perform a tightening check after the first commissioning, then periodically, to compensate for material settling or loosening due to vibrations.
A rigid and verified structure ensures the durability of the system and operational stability.
4. Risk of burns and component overheating
Motors, controllers, and drives dissipate significant power as heat. Some surfaces can reach over 70 °C in continuous operation.
Precautions to take:
Identify hot zones (motor housings, heat sinks, braking resistors, electronic radiators).
Install thermal screens or physical guards to prevent accidental contact.
Apply standardised “Hot Surface” signage (ISO 7010 – W017).
Allow for a cooling period before intervention or maintenance.
Preventing thermal risk limits skin burns and degradation of neighbouring components.
5. Conclusion
The electrification of mechanical systems combines electrical and mechanical risks that should never be separated.
A comprehensive safety approach must include:
prevention of entanglements,
protection of moving areas,
control of fastenings and
temperature control.
These good practices, combined with staff training and periodic inspection of installations, ensure safe, sustainable operation in compliance with industrial safety requirements.
*: The technical information presented in this article is provided for guidance only. It does not replace the official manufacturers' manuals. Before any installation, handling, or use, please consult the product documentation and adhere to safety instructions. Torque.works cannot be held responsible for inappropriate use or incorrect interpretation of the information provided.