Monitoring system

A method of monitoring the instantaneous operating capacity of a non-continuously rated electric motor, comprising the steps of:

• storing an absolute maximum operating temperature and a predetermined maximum permitted operating temperature of a motor;
• sensing an operating temperature of the motor;
• indicating, in response to said steps of storing and sensing, the sensed operating temperature as lying:
• a) within a safe operating range, below the predetermined maximum permitted operating temperature;
• b) within a hazardous operating range, lying between the predetermined maximum permitted operating temperature and the absolute maximum operating temperature;
• and
• c) at or above a dangerous operating point lying at or above the absolute maximum operating temperature;
• and
• operating a motor cut-out if the operating temperature of the motor exceeds the predetermined maximum permitted operating temperature, which cut-out can be manually overridden to enable continued operation of the motor in the hazardous operating range, but which cannot be manually overridden which the operating temperature of the motor reaches the absolute maximum operating temperature.