A sensor system measuring the weight of passengers in the elevator car to prevent overloading, enable load-bypass dispatch, and optimise motor torque pre-tensioning.
Full Definition
Load weighing devices use strain gauges, pressure sensors, or deflection sensors under the car platform or in the suspension rope anchor points to measure the actual car load in real time. When load reaches typically 110 % of rated capacity, the device signals the controller to inhibit new car calls and sound an overload alarm until passengers exit. The measured load value is also fed to the VVVF drive as a pre-torque signal, improving start quality by pre-energising the motor before brake release to prevent rollback. In group-controlled installations, load data informs the dispatch algorithm to skip a nearly-full car.
