Measures three-phase active and reactive energy for class B/class 1 metering.
Overview
The Circutor CEM-C21 is a static three-phase energy meter supporting class B active energy (EN50470) and optional class 2 reactive energy. This ModbusCloud template reads per-phase voltage, power, reactive power, power factor, and total power over Modbus RTU at 9600 baud.
Key readings
Voltage F1 to F3
Power F1 to F3
Total Power
Reactive Power
Cos phi F1 to F3
Use cases
Monitor per-phase voltage and power on a live cloud dashboard to detect load imbalances across three phases.
Log total active and reactive energy consumption over time for tenant billing or energy audits.
Create an alert when power factor drops below a threshold to identify potential power quality issues.
Compare energy usage across multiple CEM-C21 meters installed at different distribution boards in one building.
Generate daily or monthly energy reports for facility managers without visiting the site.
Installation
1Wire the Circutor CEM-C21 to the ModbusCloud gateway (MCG or MLP series) using a shielded RS-485 cable, connecting A, B, and GND terminals.
2Set a unique Modbus RTU slave address on the CEM-C21 using the front panel buttons, and note this address for gateway configuration.
3Confirm the CEM-C21 baud rate is set to 9600 (factory default) to match the template settings.
4In the ModbusCloud platform, add a new device and import the Circutor CEM-C21 template from the template library.
5Enter the configured Modbus slave address in the device settings and verify that live readings appear on the dashboard.
Things to watch for
Registers (11)
11 read / 0 write
Name
Address
Function
Type
Unit
Access
Power F1
1860
FC03
int32
R
Power F2
1862
FC03
int32
R
Power F3
1864
FC03
int32
R
Power
1866
FC03
int32
R
Reactive Power
1876
FC03
int32
R
Voltage F1
1842
FC03
int32
R
Voltage F2
1844
FC03
int32
R
Voltage F3
1846
FC03
int32
R
Cos phi F1
1854
FC03
int32
R
Cos phi F2
1856
FC03
int32
R
Cos phi F3
1858
FC04
uint16
R
Use directly in ModbusCloud
Import this template into your own portal with one click, or get in touch for installation support.
