The Janitza RCM 202-AB is a two-channel residual current monitoring device, specifically designed for continuous measurement and monitoring of fault currents in earthed AC systems, particularly in TN and TT networks. It detects and monitors residual currents of types A, B, and B+ in accordance with IEC 62020 standards, and is also capable of detecting sinusoidal alternating fault currents up to 20 kHz (type B+). The device is compatible with two connectable current sensors, enabling precise measurement in the range of 10 mA to 20 A (AC/DC). The integrated sensor connection monitoring detects wire breaks or short circuits per channel, preventing false alarms and enhancing system reliability.

Operation is performed via an intuitive 3-button control and a dual-color LED display with a resolution of 128 x 64 pixels, which shows measurement values and status information. The user interface is available in German, English, and Spanish, facilitating use in international environments. For integration into higher-level monitoring systems, the device features an RS485 interface with Modbus RTU protocol, enabling communication with all communication-capable Janitza Modbus master devices. Measured values and extreme values are stored with timestamps to ensure subsequent analysis and documentation.

Technical Data

• Manufacturer's Part Number: 1401627
• Type: RCM 202-AB
• Product Type: Residual Current Monitoring Device
• Measurement Channels: 2
• Measurement Range: AC/DC 10 mA to 20 A
• Application: TN and TT systems, earthed AC systems
• Standards: DIN EN 62020 / VDE 0663 / IEC 62020
• Detected Fault Current Types: A, B, B+
• Supply Voltage: 85 ... 305 V AC (50/60 Hz) – Source 1/2; 90 to 276 V AC, 50/60 Hz – Source 3
• Supply Frequency Range: 45 to 65 Hz – Source 3
• Power Consumption: 8 W – Source 3
• Dimensions: Width 71 mm, Height 90 mm, Depth 73 mm – Source 3
• Weight: 0.12 kg – Source 3
• Interface: RS485 / Modbus RTU
• Display: Dual-color LED display (128 x 64 pixels)
• Connection: Plug-in connection
• Trip Current Setting 1: 30 to 20000 mA – Source 3
• Trip Current Setting 2: 30 to 20000 mA – Source 3
• Maximum Permissible Trip Delay: 10 s – Source 3
• Minimum Adjustable Trip Delay: 0.01 s – Source 3
• Fault Memory: yes
• Residual Current Display: yes
• With Removable Terminals: yes

Note (internal)
Conflicting information regarding supply voltage: Source 1 and 2 state 85 ... 305 V AC, while Source 3 specifies 90 to 276 V AC. Both values are listed here, as no source can be clearly identified as primary or correct. All other technical data are consistent across all sources.