The CU-4E (FMH/NME/NMI) consumes a maximum of 1W. This consumption is continuous even when the load is off. When the load is on, the power consumed by the load is added to the total power input of the CU along with the power consumed by the sensor. The SU-5E sensors consume a maximum of 0.2W of DC power, which results in a maximum of approximately 0.3W of AC power, due to the efficiency of the CU internal power supply. During normal operation, the actual power consumed will be lower than these maximum values, and will also vary depending on the line voltage.
For example, the CU + Sensor will consume 1.3W Max. from the AC mains at 277VAC. The amount of power the CU uses depends on the operating voltage (120 ~ 277 VAC), and unit to unit variations.
For a 'typical' number, based on the design, validation, testing data, and a quick bench measurement at room temperature 22 degrees C:
Line Voltage CU PWR CU+SU-5E PWR
120VAC 0.43W 0.66W
240VAC 0.49W 0.75W
277VAC 0.55W 0.82W
Less than 1W is a ‘typical’ power consumption number. The “1W” is Max. value specification, which is also part of the Enlighted rating with UL, which is not to be exceeded under any operating condition).