METHOD FOR MONITORING A SAFETY CIRCUIT OF A LIFT ASSEMBLY AND MONITORING DEVICE FOR A SAFETY CIRCUIT OF A LIFT ASSEMBLY

摘要

A method for monitoring a safety circuit and a monitoring device for a safety circuit of an elevator system are based on a monitoring device for a supply voltage of a series connection of switches for monitoring the safety of devices serving the elevator operation. Safety relays are connected to the end of the series connection, which relays generate signals for an elevator controller according to the switching state of the switches. The supply voltage is set such that the voltage is constant across the relays. Since there is an upper limit value to the supply voltage available from the voltage source, the supply voltage is monitored and an error notification is generated when an upper limit value is reached. In order to permit high levels of availability of the elevator system, at least one further parameter of a curve of the supply voltage is determined and evaluated.