Power Supply
The WattsOn requires a 15-24VAC or 20-30VDC, 100mA power supply. Normal current consumption is approximately 50mA, however startup current can peak around 100mA for a second or two.
Multiple WattsOn units can be powered off of one supply, provided that the VA and amperage rating of the chosen power supply satisfies the desired load. For example, to power five (5) WattsOn units, it is recommended to use a 500mA (12VA @ 24VDC) power supply.
The power supply can be as simple as a small control or "doorbell" transformer, to a DIN mount power supply. Additionally, the power supply can be shared with other existing equipment, and potentially run via an unused twisted pair of the RS-485 communications bus. This way, the low voltage control power supply can be shared throughout the entire installation.
The design decision to separate the power supply from the metering input signals was to allow for greater installation flexibility, as well as to allow the WattsOn to operate even in the absence of input voltage signal. In such a case, the WattsOn can be polled even if the machinery it is metering is off.
Multiple WattsOn units can be powered off of one supply, provided that the VA and amperage rating of the chosen power supply satisfies the desired load. For example, to power five (5) WattsOn units, it is recommended to use a 500mA (12VA @ 24VDC) power supply.
The power supply can be as simple as a small control or "doorbell" transformer, to a DIN mount power supply. Additionally, the power supply can be shared with other existing equipment, and potentially run via an unused twisted pair of the RS-485 communications bus. This way, the low voltage control power supply can be shared throughout the entire installation.
The design decision to separate the power supply from the metering input signals was to allow for greater installation flexibility, as well as to allow the WattsOn to operate even in the absence of input voltage signal. In such a case, the WattsOn can be polled even if the machinery it is metering is off.