A refrigeration system energy controller 10 for controlling the on-Off cycle time of a refrigeration compressor motor 25. A pressure-sensing device 27 senses high and low pressure thresholds in the refrigeration low-side suction line, the high threshold event being converted to a first digital voltage that energizes the refrigeration compressor motor 25, and the low threshold event being converted to a second digital voltage that produces a fixed duration timing signal setting the minimum time duration of the compressor motor 25 on-Off cycle.