Overcurrent protection device for electrical networks and apparatuses.

摘要

Overcurrent protection device for electrical plants and apparatuses for the low voltage range. The device comprises a thermistor (1), made of a conducting polymer composite, with a positive temperature coefficient. The thermistor is connected in series with a contact device (2), which upon an overcurrent is automatically opened by the action of an excitation coil (3) connected in parallel with the thermistor. The thermistor is provided with electrodes (5) in the form of heat-absorbing bodies, which at normal motor starting currents provide a thermal delay so as to prevent unwanted tripping.