This sine-wave inverter is especially made for emergency-operation of elevators. By the ability to supply a high short–time overload condition, the safe operation of inductive loads, such as power-contactors is also possible. Electronic assemblies which have problems running with trapezoid-wave voltages will operate unproblematically.
A special warn relay gives information about low battery-voltage, over-current or high temperature of the inverter. This makes the elevator control system able to evaluate the information and e. g. finish a current drive and then stop the elevator until the fault is eliminated. This prevents people from get stuck between two floors.
In case of battery low-voltage during operation the inverter stops output to prevent the batteries from damage. The OK-relay is deactivated in this case.
The inverter is also short circuit protected. Is a short circuit detected, the inverter stops output for a short time and than switches the output on again. Is no fault detected any more, the inverter switches to normal operation. Is the short circuit detected again, 5 retries are made within 10 seconds. Then, the inverter stops output and has to be RESET manually. This leads to maximum safety and self protection.
If a fault is detected, it is displayed via LED (blink-code).