WattsOn®-MCM: Modular Multi Channel Power & Energy Platform


  • Measurement from 10-347Vac (600Vac line-to-line)
  • Modular Design, various input modules
  • From 3 to 60 current input channels
  • Any combination of single, split & 3-phase circuits
  • Per channel configurable CT ratios
  • Per channel voltage/current mapping
  • Digital communication via RS-485, Ethernet and WiFi
  • Modbus/RTU, Modbus TCP, BACnet/IP, MQTT, API, HTTP web server, HTTP Post
  • Ultra High Accuracy, High-Resolution Power and Energy measurements
  • Compatible with mA, mV, or Rogowski Coil Inputs
  • Custom virtual points are readable with Modbus and BACnet.
  • Virtual points support arithmetic across all 60 input channels
  • NEMA Enclosure

Product Description

The WattsOn-MCM is a modular power and energy metering system. The product consists of a main board, voltage interface, and expandability for up to 20 input cards (3 channels per card) a power supply and communication interface card.

The modular design allows for flexible deployment, and possibility of easy future expansion. Each AC power metering card features up to three channels of measurements, and with 20 card slots, this translates to a total of 60 possible metering points.

The on-board communication coordinator features RS-485, Ethernet and WiFi interfaces. With Modbus/RTU, Modbus TCP, HTTP Post, web server, and API, the architecture allows for flexible integration with many third-party platforms and devices. Additionally, the Elkor Cloud service may be used for monitoring and trending.

Configuration is handled through the on-board webserver, with a straightforward wizard. This allows configuration of existing and newly added cards including proper CT configuration, in addition to channel naming and channel voltage mapping.

Voltages need only be wired once into the voltage interface, which provides a safe, isolated signal to the WattsOn-MCM. This prevents the need for additional wiring, and limits the line voltages to a small area of the enclosure.

A highly flexible template and configuration design allows for user created virtual metering points. This allows a number of math functions to be performed on multiple data points, which may be used to aggregate data from user specified channels. Using the incorporated math and scripting allows for user defined calculations to be carried out on arbitrary register sets.

Future expandability means that the system can grow with demand. The plug-and-play design will feature multiple module types including Power Monitoring (Simple, Full, Advanced)**.

** Pulse/Relay Input, Pulse/Relay Output, Analog Input, Analog Output modules in development.


INPUTS: Main Board
Power Supply: 120-240VAC (internal 24VDC power supply)
Supported Wiring Types: Up to 347/600V Delta, Wye
Single-phase installations up to 347V RMS
Split-phase (two phase) installations
Frequency: 40-70 Hz nominal (30-300 Hz max)
Voltage: 20Vac - 347Vac L-N (600Vac L-L)
(450Vac L-N, 780V L-L absolute max)
Current Input Channels
Using -PM Cards
Modular Design:
  1-60 single phase
  1-20 three-phase
  1-30 split-phase
or any combination--voltage/current phasing freely assignable
Wire Size: Voltage: AWG 30-12, (AWG 16-22 recommended)
Overload: 20% continuous maintaining full accuracy. 50% momentary voltage overload
INPUTS: Power (-PM) Cards
(Model Dependent):
-mA model -mV model -RC model
   Input Rating: Up to 200mA CTs (ie: Elkor mA CTs) 333mV output CTs (400mV max) Up to 360mV via Rogowski Coils
   Input Impedance: 1.5Ω typ 800kΩ min, 1.2MΩ typ 600kΩ min
Wire Size: AWG 24-12
Overload: 20% continuous maintaining full accuracy. 100% momentary current overload
INPUTS: Input (-IM) Cards
Analog Input Modes:
  • 0-10VDC
  • 4-20mA
  • Pulse/Status (wet or dry contact)
Specifiations: 0-10VDC Mode 4-20 mA Mode Pulse Mode
In Development
Modbus/RTU RS-485 2-wire, 9600 to 230400 baud
Ethernet/WiFi Modbus/TCP, BACnet/IP, MQTT, HTTP Post, Webserver, API
Auxilliary Bus: RS-485 2-wire Modbus/RTU, for direct communication with cards
Display (optional): Color Touchscreen Graphical HMI
Through front panel (or remote) installation
Current (A): 0.1% typ 0.2% max
Voltage L-N (V): 0.25% typ 0.3% max
Voltage L-L (V): 0.25% typ 0.3% max
Power (W, VA, VAR)*: 0.2% typ 0.5% max
Energy (Wh, VARh, VAh)*: 0.2% typ 0.5% max
Power Factor: 0.4% max
Frequency: 0.01% max
Input Bandwith: 2 kHz (33rd Harmonic @ 60Hz, 40th Harmonic @ 50Hz)
Data Update Frequency: 2 Hz (every 500ms)
* Available measurement parameters depend on card model (see below)
Dimensions: 12" x 10" x 4" W x L x H
Mounting: Wall Mount NEMA4X Enclosure*
*Rating is NEMA1 with optional through-panel LCD touchscreen.
Operating Temperature: -40°C to +70°C
Storage Temperature: -65°C to +85°C
Humidity: 10 to 90% non-condensing
Safety: UL Listed (#E250395)
Isolation: 3,500VAC (min) input-to-output
Electromagnetic Emissions: FCC part 15 Class A

Power Metering Cards

  • WMC-PM-L-xy: (Lite): Three channels of V, A, PF, kW, kWh (absolute)
  • WMC-PM-P-xy: (Plus): Three channels of V, A, PF, kW, kVAR, kVA, kWh, kVARh, kVAh (import/export)
    Where -xy represents the desired CT input type (-mA, -mV, -RC)
  • WMC-IM: Three Channel Analog/Digital input (0-10VDC, 4-20mA, wet/dry pulse or relay) -- In Development

Front Panel Display

Optional Front Panel Touchscreen shows dynamic measurements and virtual data points

Web Server

Built in webserver for quick, visual setup and monitoring


Modbus Commander LITE
E3/E4 Ethernet Finder Tool
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