Machine Brake: Spring-Applied Fail-Safe, Two Independent Elements, Holds 125% Load and Stops Fully Loaded Car EN 81-20

The machine brake (electromechanical brake, EC brake, or holding brake) is a friction brake integrated into the elevator drive machine. It is spring-applied: when the brake coil is de-energised, springs apply the brake pads or shoes to the brake drum or disk, stopping and holding the shaft. It is electrically released: energising the coil compresses the springs and releases the brake, allowing the motor to drive the sheave. EN 81-20 requirements: (1) The machine must be fitted with at least one brake acting on the mechanical transmission between the drive sheave and the motor; (2) For elevators with rated speed >0.3 m/s, the machine must have two independent braking elements (circuits) — if one fails, the other must still stop and hold the fully-loaded car; (3) Stopping performance: the fully-loaded car running at rated speed downward must be stopped within the deceleration limits by the brake alone (without the motor); (4) Holding performance: the brake must hold 125% of rated load (static test); (5) The brake must be a positive-acting type — fail-safe on power loss; (6) Brake wear monitoring: brake pad/shoe wear indicators or micro-switch monitoring is required to detect brake pad wear and warn before safety margin is lost. Brake types: drum brake (most common in older geared machines), disk brake (gearless machines). The machine brake is separate from the safety gear — the gear operates on the guide rails, the brake on the machine shaft.

View All Terms