A system comprising: a compressor having an electric motor and an electrical enclosure configured to house electrical terminals for connecting a power supply to said electric motor; a sensor module for said compressor, said sensor module including: a plurality of inputs connected to a plurality of sensors (54, 56, 58, 60, 150, 152, 154, 156, 158, 160, 161, 163) that generate a plurality of operating signals associated with operating conditions of said compressor; a processor connected to said plurality of inputs that records multiple operating condition measurements from said plurality of operating signals, wherein said processor is disposed within said electrical enclosure of said compressor; a communication port connected to said processor for communicating said operating condition measurements to a control module that controls said compressor; and characterised in that: said electric motor operates at a first voltage, said sensor module operates at a second voltage, said power supply operates at said first voltage and said second voltage is less than said first voltage; said module further comprising: a transformer located within said electrical enclosure that generates said second voltage from said power supply. a compressor having an electric motor and an electrical enclosure configured to house electrical terminals for connecting a power supply to said electric motor; a sensor module for said compressor, said sensor module including: a plurality of inputs connected to a plurality of sensors (54, 56, 58, 60, 150, 152, 154, 156, 158, 160, 161, 163) that generate a plurality of operating signals associated with operating conditions of said compressor; a processor connected to said plurality of inputs that records multiple operating condition measurements from said plurality of operating signals, wherein said processor is disposed within said electrical enclosure of said compressor; a communication port connected to said processor for communicating said operating condition measurements to a control module that controls said compressor; and characterised in that: said electric motor operates at a first voltage, said sensor module operates at a second voltage, said power supply operates at said first voltage and said second voltage is less than said first voltage; said module further comprising: a transformer located within said electrical enclosure that generates said second voltage from said power supply. a plurality of inputs connected to a plurality of sensors (54, 56, 58, 60, 150, 152, 154, 156, 158, 160, 161, 163) that generate a plurality of operating signals associated with operating conditions of said compressor; a processor connected to said plurality of inputs that records multiple operating condition measurements from said plurality of operating signals, wherein said processor is disposed within said electrical enclosure of said compressor; a communication port connected to said processor for communicating said operating condition measurements to a control module that controls said compressor; and characterised in that: said electric motor operates at a first voltage, said sensor module operates at a second voltage, said power supply operates at said first voltage and said second voltage is less than said first voltage; said module further comprising: a transformer located within said electrical enclosure that generates said second voltage from said power supply. said electric motor operates at a first voltage, said sensor module operates at a second voltage, said power supply operates at said first voltage and said second voltage is less than said first voltage; said module further comprising: a transformer located within said electrical enclosure that generates said second voltage from said power supply.