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
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Applications
![](images/WattsOn-Mark_II-Application.webp)
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 | |||||
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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 |
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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) |
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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) |
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Overload: | 20% continuous (voltage & current) maintaining full accuracy. 100% momentary current overload |
OUTPUTS | |||||
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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 |
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Indicators: | LEDs for: Status, Voltage, Current, Relay State, Communication |
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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 | |||||
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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 |
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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 | |||||
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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) |
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Mounting: | DIN Rail Mount 2-point screw wall mount |
ENVIRONMENTAL | |||||
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Operating Temperature: | -40°C to +70°C | ||||
Storage Temperature: | -65°C to +85°C | ||||
Humidity: | 10 to 90% non-condensing |
COMPLIANCE | |||||
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Safety: | UL 508 Listed (#E250395) | ||||
Isolation: | 3,500VAC (min) input-to-output | ||||
Electromagnetic Emissions: | FCC part 15 Class B (residential and industrial) |
Measured Parameters
Part Number Generator
WattsOn-Mark II
Application Notes
Interface Hardware
Compatibility Verified by Elkor | |
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FTDI USB-485 Converter | USB-RS-485 Cables and Modules |
USB-485 Converter | Low cost USB-RS-485 Converter |