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Product Discontinued
Information is for legacy purposes
Replaced by WNC for LonWorks

AC Power Measurement for LonWorks® Networks:

True Power
Reactive Power
Power Factor
Individual Phase Measurements

This product line is no longer being sold, information is for legacy purposes.

The WNB series WattNode Plus for lonWorks has been replaced by the WNC series WattNode Plus for LonWorks

Instructions (PDF) on migrating to the new models.

The WattNode® Plus for LonWorks® is a networked multi-functioned digital power meter and monitor. The WattNode Plus offers true RMS power metering, plus demand, plus individual phase voltage and current, plus individual and average power factor, plus reactive power and energy metering, plus frequency. Typical applications include energy monitoring, submetering, demand management, power factor control and phase-load monitoring.

Our WattNode Plus measures and communicates the following quantities over a twisted pair (FTT-10) or power line carrier (PLT-22) network.

  • True RMS Power – Watts (Phase A, Phase B, Phase C, All Phases)
  • Reactive Power – VARs (Phase A, Phase B, Phase C, All Phases)
  • Power Factor (Phase A, Phase B, Phase C, All Phases)
  • True RMS Energy – Watthours (Phase A, Phase B, Phase C, All Phases)
  • Reactive Energy – VAR-hours (All Phases)
  • AC Frequency
  • Computed RMS Voltage (Phase A, Phase B, Phase C)
  • Computed RMS Current (Phase A, Phase B, Phase C)
  • Demand
  • Peak Demand

Easy installation saves you time and money. The WattNode is small enough to fit entirely within a standard electrical panel and the screw terminals unplug for easy wiring.

The complete WattNode Plus family measures 1, 2 or 3 phases in delta (3 phase, 3 wire) or wye (3 phase, 4 wire) configurations. With voltage ratings from 120 to 600 VAC and current transformer (CT) ratings from 5 to 4000 amps, there is a WattNode Plus and CT combination to meet the nearly all of your AC power measurement requirements.

Accuracy of the WattNode is 0.5% of reading over a wide range of power factor and harmonic content. The WattNode measures true RMS power even with leading or lagging power factor and chopped or distorted waveforms. This makes the WattNode ideal for monitoring motors and pumps controlled by variable speed drives.

To assure reliability and accuracy, each WattNode is tested and calibrated by a custom, automated production system. A key part of the production process is calibration with NIST traceable standards. To assure the initial calibration accuracy is maintained, the WattNode has been designed with fixed, precision resistors, not potentiometers, in its measurement circuit.

Our safe CTs, with integral burden resistors, produce a voltage proportional to the load current. At rated current the voltage is only 0.333 VAC. Split core CTs quickly install on existing wiring and solid core CTs can prevent tampering. Bus bar CTs are available in a variety of standard sizes, plus custom designs up to 10″ x 10″ (254mm x 254mm) and 4000A.


  • WNB-3Y-208-FT10
  • WNB-3Y-400-FT10
  • WNB-3Y-480-FT10
  • WNB-3Y-600-FT10
  • WNB-3D-240-FT10
  • WNB-3D-480-FT10



  • Line powered
  • FCC Class B
  • CE Mark
  • Operating Voltage Range: &plusminus;20% of nominal
  • Power Line Frequency: 50 or 60 Hz
  • CT Input: 0 – 0.5 VAC operating, 3 VAC maximum

Measurement Configurations

  • Three phase, four wire
  • Three phase, three wire


  • 0.45% of reading + 0.05% of full scale through 25th harmonic


  • Operating Temperature: -30° to 60°C
  • Humidity: Up to 90% RH (non-condensing)

Case Dimensions



  • High impact, ABS plastic
  • Flame Resistance Rating: 94V-0, IEC FV-0
  • Size: 143mm × 85mm × 38mm (5.63″ × 3.34″ × 1.5″)
  • Weight: 295gm (10.4oz)

Connectors: Euroblock style pluggable terminal blocks

  • Green: 22 to 12 AWG (1.0mm – 3.2mm), 600 V
  • Black: 22 to 12 AWG (1.0mm – 3.2mm), 300 V

Datasheet, Manual, XIF File, and Application Notes