Modbus Connected Power and Energy Monitoring transducers from Logic Beach

WNC-MB Modbus Power Meter
installed in Residential Service

For applications requiring detailed electrical power information, Logic Beach offers a variety of Modbus enabled electrical parameter meters. These meters can measure electrical loads and provide multiple electrical parameters via a Modbus RTU interface including power (kW), energy (kWh), phase voltages, phase currents, power factor and much more.

The IntelliLogger family of data loggers configured as a Modbus RTU Master can interrogate and log user specified parameters from one or more connected Modbus RTU Slave power meters. Simultaneous with the readings logged via the Modbus interface, the IntelliLogger can be sampling, processing, logging and reporting hard-wired inputs (e.g. thermocouples, pressures, flows, etc) as well.

The Modbus RTU interface uses an RS-485 connection between the IntelliLogger and the meters. Each device (meter or other Modbus Slave device on the RS-485 network) is assigned a unique device address allowing up to 15 Modbus devices to be connected to a single IntelliLogger.

Details on the various Modbus connected multi-parameter meters follow. Addtiional details on Modbus and the Modbus option for the IntelliLogger data logging instrument family are available on the IntelliLogger Modbus Interface Options page.

WNC-MB Modbus Energy Meter; Single Phase or Poly-Phase with Separate CT’s

The WNC-MB family of Modbus output Energy Meters are flexible in configuration and power level due to user interchangable current transformers (CT’s) and the Modbus interface. Via the Modbus interface, the connected Modbus RTU Master device (e.g. the IntelliLogger data logging and alarming instrument from Logic Beach) can be programmed to read and log one or more desired parameters from one or more connected meters.

The WNC-MB Energy Meters are available for various wiring configurations and voltages and can be used in single phase as well as poly-phase applications. Terminal strips are provided for CT and Voltage Sense wiring connections. A wide range of compatible CT’s are available.

In operation, the WNC-MB meter samples, calculates and updates various electrical parameters every second. These parameters are held internally in Modbus registers (memory locations) which are in turn read periodically by the connected Modbus RTU Master device.

Use of the WNC-MB meter with the Logic Beach IntelliLogger provides a powerful solution for R&D, performance testing, energy audits, M&V applications for utility rebates and other energy monitoring applications. With the IntelliLogger and WNC-MB system, data logging, local alarming, reporting via FTP and Email as well as Web page serving of current values is readily handled… all via the IntelliLogger and the powerful HyperWare-II icon-based programming software.

[Example IntelliLogger Chiller M&V Data Collection Program]

WNC-MB General Specifications:

Measured Parameters:

True RMS Power - Watts (Phase A, B, C and Sum)
Reactive Power - VARs (Phase A, B, C and Sum)
Power Factor - (Phase A, B, C and Average)
True RMS Energy - Watthours (Phase A, B, C and Sum)
Reactive Enrgy - VAR-hours (Sum)
AC Frequency
RMS Voltage (Phase A, B and C)
RMS Current (Phase A, B and C)
Demand and Peak Demand

Accuracy: Typical 1% Rdg plus CT error (typically also 1%)
Frequency Measurement Range: 48-62 Hz
Line Voltages Supported: 120 to 600Vac (per model)
Current: 5% to 100% of rated current
Current Transformers: 0.333Vac RMS
Output: Modbus RTU, RS-485 2-wire, 9600 and 19,200 baud, N81
Price range: $300 to $400 plus split-core CT’s (~$50 to $80 each)
Contact Logic Beach