Janitza Three-Phase Energy Meter with CT Connection B24 312-10J (1401360)

Facility managers and electrical engineers install the Janitza B24 312-10J in low-voltage distribution boards to capture three-phase active and reactive energy data. The meter connects indirectly via current transformers with selectable 1 A or 5 A secondary current, making it suitable for retrofits and new installations where high currents are present. Its LCD shows accumulated energy values clearly, while two S0 pulse outputs and an RS485 Modbus RTU interface allow integration into building management or energy monitoring systems.

Key specifications

• Three-phase active and reactive energy measurement
• Indirect connection via current transformers (CT), secondary 1 A or 5 A
• Nominal voltage 3x230/400 V AC, range 0.8–1.2 Un
• Frequency 50/60 Hz
• Accuracy class 1 (active energy, MID Class B), class 2 (reactive energy)
• LCD display, 7-digit
• Interfaces: 2x S0 pulse output, RS485 (Modbus RTU)
• Two tariffs
• MID certified (Module B+D)
• DIN rail mounting, 4 modules wide
• Protection class IP20 front, IP51 terminals
• Operating temperature -25°C to +55°C
• Maximum current 6 A (internal circuit)
• Starting current 0.004 Ib
• Energy registers: active import/export, reactive import/export

Why choose it

The B24 312-10J provides MID-certified accuracy for billing applications, with flexible CT compatibility and standard communication options. Its compact 4-module DIN rail housing saves space in distribution panels.

Ideal use cases

• Sub-metering in commercial buildings
• Energy data acquisition for ISO 50001 management
• Monitoring of production lines with high current loads
• Integration into Modbus-based SCADA or BMS systems

Good to know

The meter is designed for indirect measurement only; external current transformers are required. The RS485 interface supports Modbus RTU protocol for remote reading and configuration.