Mechanical Hazards: Drop, Tip and the Stability of a Bench Instrument

Mechanical hazards in IEC 61010 cover more than sharp edges. They include the stability of the equipment, the effect of a drop or an impact, the risk from moving parts, and the risk that a heavy instrument falls off a bench onto a user.

Stability and tip

Floor-standing and bench equipment is assessed for stability on a plane inclined at a defined angle, and for resistance to being pushed. Equipment with a door, a drawer or a plug-in module is tested in the least favourable configuration, because an open drawer moves the centre of gravity. A design that is stable empty and tips when loaded is a common finding.

Drop and impact

Hand-held and portable equipment is dropped onto a defined surface from a defined height, in several orientations. The acceptance criterion is not cosmetic: after the drop, clearances must still be met, the enclosure must still prevent access to live parts, and no hazardous part may become accessible. Inspecting only for cracks misses the reduced clearance that a deformed moulding produces.

Moving parts

Guards, interlocks and the force limits for moving parts are assessed where the equipment has motors or actuators. An interlock that can be defeated by a finger, or a guard held by a single screw, is a finding regardless of how well it works in normal use.

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• Instruction Manual Requirements: The Clauses Test Houses Read First