THERMAL PROTECTION FOR ELECTRICAL INSTALLATIONS AND FITTINGS

摘要

An electrical fitting such as a socket (1) is provided with a thermal cut-out (16) to disconnect the power supply to the socket (1) in response to detection of an abnormal increase in temperature caused, for example, by a loose or faulty connection. The cut-out (16) is connected across the earth and neutral terminals and is normally open and is closed when an abnormal temperature is detected to cause a fault that trips a residual current detector (RCD) to disconnect the power supply to the socket (1). The cut out (16) may be a switch (17) operable by a temperature responsive actuator (18). In one embodiment (Figure 4) , the cut-out comprises contacts held apart (open circuit) by a thermally responsive spacer that melts at a pre determined temperature to allow the contacts to come together (closed circuit) to trigger the RCD (Figures 4 and 5).