Attached is a wiring diagram that shows how to connect a Wattnode kWh Transducer to a HOBO H21-002 Micro Station to log energy consumption in a 3-phase circuit.

Note: The wiring from the H21-002 to the Wattnode would be the same for 2-phase (or split-phase) and single-phase circuits.


Installing transducers in an energized electrical enclosure or on any energized conductor can result in severe injury or death. These transducers are for installation by qualified personnel only. To avoid electrical shock, do not perform any installation or servicing of these transducers unless you are qualified to do so. Disconnect and lock-out all power sources during installation and servicing. Please read transducer user manuals for instructions and use.

Helpful Links:

H21-002 Micro Station

Wattnode kWh Transducer (480VAC version in the example)

Working with HOBO data loggers for Energy Logging Training Course


Tech Note
Getting Started
Troubleshooting & Maintenance