WattsOn®-Mark II: Precision Energy Meter

Features

  • ANSI C12.1-2022 Class 0.1 Accuracy, Four-Quadrant
  • California CSI PBI Eligible
  • High-Resolution Power and Energy measurements
  • Fast update (100ms) for all power readings
  • Per phase instantaneous and accumulated data
  • Ultra-High Dynamic Range simplifies CT options
  • Compatible with mV, mA, 5A and Rogowski Coil Inputs
  • Digital communication via RS-485 (Modbus/RTU or BACnet MS/TP)
  • Customizable Modbus Register Map
  • Compatible with common Solar Industry Modbus Specifications
  • Alarm / Pulse Outputs
  • DIN and wall-mount enclosure
  • Optional Display with Datalogging and Real-Time Clock
  • Optional Ethernet with Modbus/TCP, BACnet/IP or web server with user configurable POST capability

Applications

Ideal for Energy Management, Solar, Export Limit, Building Automation and OEM Applications.

The WattsOn-Mark II Precision Energy Meter uses cutting-edge metering technology to provide unprecedented accuracy, resolution and metering performance for any electrical installation.

WattsOn monitors each phase individually and incorporates the functions of single-phase, split-phase, and three-phase meters.

Product Description

The WattsOn-Mark II Precision Energy Meter utilizes advanced metering technology to implement a multi-function power and energy meter into a small, cost-effective package. WattsOn-Mark II provides a unique solution for monitoring virtually any wiring installation including single phase, split phase and three phase loads. It accepts up to 600V (line-to-line) directly, without the need for potential transformers. It may be configured for use with industry standard 5A CTs, 333mV CTs, mA CTs (such as Elkor's line of safe mA split and solid core CTs) or Rogowski Coil flexible CTs.

The WattsOn-Mark II offers full four-quadrant metering. All parameters are metered and accumulated on a per-phase basis. Instantaneous power (W, VA, VAR) feature a high update rate (100ms), other parameters are updated every 500ms. The high sampling rate, true-RMS inputs may be used even with distorted waveforms, such as those generated by variable frequency drives and SCR loads, up to the 30th harmonic.

The meter provides comprehensive per phase data, including Volts, Amps, Real Power, Reactive Power, Apparent Power, Voltage Angle, Power Factor and Frequency, Quadrant, Import/Export/Net Wh/VAh and per Quadrant VARh.

All models include Ultra-High Resolution and Dynamic Range. This feature allows mA input meters to be user configured and no longer requires the CT model and ratio to be specified at the time of ordering, simplifying meter and CT selection. The wide dynamic range of the current inputs ensures high accuracy and resolution even at very low measurements. Precise CT ratios and phase compensation may be field programmed for ultimate accuracy. Additionally, the meter may be configured with individual CT ratios per-phase, allowing for metering asymmetrical loads such as individual building branch circuits.

Measurements are available via the RS-485 output port (Modbus/RTU or BACnet MS/TP). In addition, two solid-state relay outputs are provided and may be software configured for pulse, status or alarm triggers, on any measured parameter. An on-board graphic LCD display, real-time clock and data logging are available as an option.

The meter may be optionally equipped with an integrated BACnet/IP gateway, or an ETnet (Ethernet module providing Modbus/TCP, web server, as well as HTTP post capability).

Specifications

INPUTS
Power Supply: 12-30 VDC or 24VAC, < 2VA
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: -5A model -mA model -mV model -RC (-RCH optional) model
   Input Rating: 5A nominal via 5A output CTs (10A max) 200mA via mA CTs (ie: Elkor "Safe" mA output CTs) 333mV output CTs (400mV max) 360mV (720mV optional) via Rogowski Coils
   Input Impedance: 0.05Ω max 1.5Ω typ 800kΩ min, 1.2MΩ typ 600kΩ min
Wire Size: Voltage: AWG 30-12, (AWG 16-22 recommended)
Current: AWG 24-12, (AWG 12-16 recommended for 5A CTs)
Overload: 20% continuous (voltage & current) maintaining full accuracy. 100% momentary current overload
OUTPUTS
Modbus/RTU (-M1): RS-485 2-wire, 9600 to 230400 baud
BACnet MS/TP (-M2): RS-485 2-wire, 9600 to 115200 baud
Expansion Bus: RS-485 2-wire, for accessory expansion
Relay: 2x Solid-State Relay Outputs (100 mA @ 50V max)
User Programmable for alarm, status or pulse output
Indicators: LEDs for: Status, Voltage, Current, Relay State, Communication
Display (-DL): Back-lit Graphic LCD Display 128x32
Ethernet (-E4): ETnet module (integrated) featuring Modbus/TCP, BACnet/IP, Webserver, HTTP POST, API, MQTT, SSL
ACCURACY
Standards: Supports EN 50470-1, EN 50470-3, IEC 62053-21, IEC 62053-22, and IEC 62053-23 standards.

ANSI C12.20 Class 0.2 Accuracy Certified by 3rd Party NRTL
exceeds ANSI C12.1-2022 Class 0.1 accuracy requirements
Current (A): 0.05% typ 0.1% max
Voltage L-N (V): 0.1% typ 0.2% max
Voltage L-L (V): 0.2% typ 0.3% max
Power (W, VA, VAR): 0.1% typ 0.2% max
Energy (Wh, VARh, VAh): 0.1% typ 0.2% max
Power Factor: 0.2% max
Frequency: 0.01% max
Input Bandwith: 2 kHz (33rd Harmonic @ 60Hz, 40th Harmonic @ 50Hz)
Data Update Frequency: 10Hz (every 100ms) for W, VA, VAR
2 Hz (every 500ms) for all others
MECHANICAL
Dimensions: 4.2" x 4.3" x 2.4" W x L x H
Mass: 0.15 kg (-mA and -mV models)
0.23 kg (-5A-DL model)
Mounting: DIN Rail Mount
2-point screw wall mount
ENVIRONMENTAL
Operating Temperature: -40°C to +70°C
Storage Temperature: -65°C to +85°C
Humidity: 10 to 90% non-condensing
COMPLIANCE
Safety: UL 508 Listed (#E250395)
Isolation: 3,500VAC (min) input-to-output
Electromagnetic Emissions: FCC part 15 Class B (residential and industrial)

Measured Parameters

Voltage
(A, B, C, Avg, AB, AC, BC, Avg)
Current
(A, B, C, Avg)
Active Power
(A, B, C, Total) - Bi-directional
Apparent Power
(A, B, C, Total)
Reactive Power
(A, B, C, Total) - Bi-directional
Power Factor
(A, B, C, System) - Bi-directional
Active Quadrant
(A, B, C, System)
Voltage Phase Angle[°]
(AB, AC, BC)
Import/Export Energy
(A, B, C, Total)
Inductive/Capacitive Energy
(A, B, C, Total)
Apparent Energy
(A, B, C, Total)
Total Demand Power
(W)

Part Number Generator

WattsOn-Mark II

Model
M1
RS-485 (Modbus/RTU), 2x pulse out

M2
RS-485 (BACnet MS/TP), 2x pulse out

E4
Ethernet / WiFi
Modbus/TCP, BACnet/IP, webserver, MQTT, HTTP Post
2x pulse out


CT Input
mA

333mV

5A

Rogowski Coil


Display
Yes

No


Model
M1
RS-485 (Modbus/RTU), 2x pulse out

M2
RS-485 (BACnet MS/TP), 2x pulse out

E4
Ethernet / WiFi
Modbus/TCP, BACnet/IP, webserver, MQTT, HTTP Post
2x pulse out


CT Input
mA

333mV

5A

Rogowski Coil


Display
Yes

No


Part Number

Software

Modbus Commander LITE
v1.14.0.0
E3/E4 Ethernet Finder Tool
BACnet MS/TP Configuration Utility

Interface Hardware

Compatibility Verified by Elkor
FTDI USB-485 Converter USB-RS-485 Cables and Modules
USB-485 Converter Low cost USB-RS-485 Converter
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