What is a shutdown input?

A shutdown input is a signal input that allows a power supply to be shut down by means of an externally supplied voltage or a simple switch. A shutdown input is galvanically isolated from the input voltage and can be supplied by separated extra-low voltage (SELV) circuits.

A power supply that is shut down will switch on occasionally to supply the electronic monitoring system with power. At no load or when the output currents are very low, small voltages (<4 V) and currents (<2 mA) can be seen at the output.

The shutdown input does not meet any safety requirements.