Electric switch current monitoring method

摘要

The current monitoring system is used for a switch (1) connected in series with an electrical load (5) and switched ON and OFF via a separate control device. The signal for the latter is regularly interrupted after a freely selected interval from the switching in phase, sufficient for the clamp voltage at the switch contacts to be restored.The load may be a heater. A fault indication is supplied when the clamp voltage in the opening phase of the switch occurs late. Pref. a fault indication is provided when the clamp voltage does not correspond to the voltage being switched.