Crompton frequency protectors give continuous surveillance of the monitored circuit. When the frequency moves outside the set point limit for longer than the time delay, the relay will operate giving an alarm control or tripping signal. An illuminated LED indicates when the relay is energised. Since speed is proportional to the frequency, this protector can be used to monitor over and under-speed and to protect mains supplies, computer supplies and standby supplies for industrial, hospital or marine use.
