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  • New itemTop seller   Modular three-phase energy meter | CT-operated 5(6) A | 3×230/400 V | RS485 Modbus | detachable display | DIN / panel | Carlo Gavazzi EM21072DAV53XOSX

    Modular three-phase energy meter | CT-operated 5(6) A | 3×230/400 V | RS485 Modbus | detachable display | DIN / panel | Carlo Gavazzi EM21072DAV53XOSX

    Code: EM21072DAV53XOSX
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    Three-phase energy meter for connection via current transformers (…/5 A) in 3×230/400 V networks. RS485 Modbus RTU, programmable pulse output and a patented detachable display – mounts on a DIN rail or in a panel door. Non-MID version – for non-billing (internal) metering.

  • Product description

    Modular three-phase energy meter | CT-operated 5(6) A | 3×230/400 V | RS485 Modbus | detachable display | DIN / panel | Carlo Gavazzi EM21072DAV53XOSX

    The Carlo Gavazzi EM21 72D (code EM21 72D AV5 3 X O S X) is a compact three-phase energy meter connected via current transformers with a 5 A secondary. It is intended for higher-current incomers and feeders where metering and key network values are needed in a SCADA or BMS system via RS485 Modbus RTU.

    Key point:
    Because current is measured through CTs, the meter suits an incomer of any size – you just pick the right transformer and enter its ratio (up to 999). The patented detachable display lets the same device be mounted on a DIN rail or in a panel door (68×68 mm cut-out). This version is non-MID – readings are for internal metering and energy management.
    Connection
    Via CT, 5(6) A
    Network
    400 V L-L
    Interface
    RS485 Modbus RTU
    Mounting
    DIN or panel
    ℹ
    Bidirectional metering
    For this code the manufacturer's datasheet does not state a separate exported energy register – total kWh and kvarh are accumulated. If import and export must be seen separately, choose a model with clearly specified bidirectional metering.

    Communication interfaces and integration

    RS485 Modbus RTU (JBUS)
    2-wire port up to 1000 m, 9600 bps, up to 247 addresses, 4000 V RMS insulation – data to SCADA, BMS, PLC or an energy management system.
    Pulse output (opto-MOSFET)
    Programmable 0.01–9.99 kWh/pulse, up to 70 mA, up to 260 V AC/DC – for a pulse counter, PLC or data logger.

    Operating principle

    Current circuits connect via external current transformers (…/5 A), voltage inputs directly to the 400 V L-L network; the device is powered from the measured voltage (VL1–N, 18–260 V AC). It mounts on a DIN rail (4 modules) or, with the display detached, in a panel door.

    It measures TRMS voltages, currents, power, reactive power, PF, frequency and phase sequence, and scales energy by the programmed CT (and VT) ratio.

    The result is total kWh and kvarh plus instantaneous values on the LCD, over RS485 Modbus RTU and on the pulse output.

    Why choose the Carlo Gavazzi EM21 72D?
    One compact device for a high-current incomer: CT connection, Modbus and flexible mounting. The detachable display is especially handy when the metering part sits inside the panel and the readout on the door.

    Technical specifications

    Product type Modular three-phase energy meter
    Manufacturer / model Carlo Gavazzi EM21 72D
    Full code EM21 72D AV5 3 X O S X
    Connection Via current transformers (…/5 A)
    Current range 5(6) A; overload 6 A continuous, 120 A for 500 ms
    Voltage 400 V L-L (3×230/400 V)
    Frequency 50/60 Hz
    Systems 3-phase 4- or 3-wire, 2-phase, 1-phase (programmable)
    CT ratio Programmable up to 999
    Accuracy class kWh: 1 (EN 62053-21), B (EN 50470-3); kvarh: 2 (EN 62053-23)
    MID No (X version) – for non-billing (internal) metering
    Tariffs Not stated
    Measured values W, var, PF, Hz, phase sequence; VLL, VLN, A; total kWh and kvarh
    Interfaces RS485 Modbus RTU (JBUS), pulse output
    Pulse output Opto-MOSFET, 0.01–9.99 kWh/pulse, up to 70 mA, up to 260 V AC/DC
    Power supply Self-powered 18–260 V AC (VL1–N), ≤2 VA / 1 W
    Display LCD 2 lines (7 + 3 digits), detachable
    Modules / dimensions 4 DIN modules, 72×72×65 mm
    Panel cut-out 68×68 mm
    Protection rating Front IP50, terminals IP20
    Operating temperature −25…+55 °C
    Standards IEC 60664, IEC 61010-1, EN 62053-21, EN 62053-23, EN 50470-3; CE, cULus

    Main functions

    • CT connection – suits an incomer of any size
    • RS485 Modbus RTU – data to SCADA, BMS or PLC
    • Detachable display – DIN or panel mounting
    • Network parameters – V, A, W, var, PF, Hz, phase sequence
    • Programmable pulses – 0.01–9.99 kWh/pulse
    • Self-powered – no separate power supply needed

    How does it differ from similar models?

    Eastron SDM630MCT-2T Also CT-operated with RS485 Modbus, but MID certified with 2 tariffs – when readings are used for billing.
    Eastron SDM630MCT-ML-1 CT-operated, Modbus, MID – an MID alternative for mid-range projects.
    Eastron SMART X96-1 96×96 panel meter via CT with Modbus and MID – panel mounting only.
    Schneider PowerLogic PM5110 / PM5330 CT-operated panel power meters – when broader power quality analysis is needed.

    Where is it used?

    • CT-metered building and factory incomers
    • High-power feeders and distribution boards
    • SCADA and BMS energy monitoring
    • Compressor rooms, pump stations, refrigeration
    • Panel-door readout points
    • Energy audits and cost allocation to departments

    Use by need

    For automation engineers.
    Modbus RTU data from a high-current line without extra converters.
    For panel builders.
    One device for DIN rail or door – fewer different part numbers.
    For energy managers.
    Clear kWh, kvarh and PF values for internal cost control.

    Practical use

    If a factory's 250 A incomer must be visible in the BMS, fit three 250/5 A current transformers, enter a CT ratio of 50 in the EM21 and connect the RS485 line – data appears in the Modbus system, and the display can be moved to the panel door.

    Pros

    • CT connection – no current limit, set by the transformer
    • RS485 Modbus RTU as standard
    • Detachable display: DIN or panel mounting
    • Self-powered from the measured voltage
    • Programmable CT/VT ratio
    • Compact – 4 DIN modules

    Cons / limitations

    • No MID (X version) – for billing choose the Eastron SDM630MCT-2T or SDM630MCT-ML-1
    • External current transformers required
    • No tariff function stated in the datasheet
    • Bidirectional metering not stated for this code
    • Front IP50 – install in an enclosed panel

    Safety and installation notes

    • Installation and wiring must be done by a qualified electrician with the supply isolated
    • Never open a CT secondary circuit under load – short it first
    • Protect voltage circuits with fuses
    • Enter the CT ratio correctly and keep phase correspondence between voltage and current
    • Run the RS485 line in twisted-pair cable with terminators at both ends

    Quick selection guide

    Via CT …/5 A
    RS485 Modbus RTU
    DIN or panel
    Non-MID
    Suitable when you need:
    • Metering on a high-current line
    • Data in a Modbus system
    • A readout on the panel door
    Check before use:
    • That MID is not required for billing
    • CT secondary 5 A and ratio
    • That the network is 400 V L-L
    Important reminder: This version is not MID certified – its readings are not valid for fiscal metering. The meter also does not replace protective devices or a power quality analyser.

    FAQ

    Is this model direct-connected?
    No, the AV5 version connects via current transformers with a 5 A secondary.
    Is it MID certified?
    No, the final letter X means the non-MID version; only PF versions are MID certified.
    What does S mean in the code?
    The RS485 Modbus RTU port.
    What does O mean?
    One static opto-MOSFET pulse output.
    Can it be panel mounted?
    Yes, the detachable display fits a 68×68 mm cut-out.
    Does it need a separate supply?
    No, it is powered from the measured voltage VL1–N.

    Wiring diagram via current transformers

    Carlo Gavazzi EM21 72D – wiring diagram via current transformers, 3 phases 4 wires

    Click the diagram to open it larger. Marked: ① current transformer wiring, ② voltage measurement, ③ supply, ④ RS485.

    ⚠ This diagram is for guidance only and may contain inaccuracies. Before connecting, check against the manufacturer's instructions and the device markings.
    The qualified electrician carrying out the installation is responsible for it. UAB „Elektrotechnikos sprendimai“ accepts no liability for connections or possible errors.

    Most common wiring mistakes

    • CT reversed or S1/S2 swapped – negative power, energy counted as export.
    • Phase connected to terminal 1 – 1 is a current input: short circuit.
    • N (10) not connected – meter has no supply, does not work.
    • CT and voltage from different phases – wrong power and cos φ.
    • SYS 3P.n or CT ratio not set – wrong readings.
    • CT secondary opened under load – dangerous voltage, CT damage.
    • RS485 A− (14) and B+ (15) swapped – no communication.
    • Jumper 15–16 not on the last device – intermittent communication.

    Documents and sources

    Diagram prepared on 2026-10-01 from the manufacturer's instructions. It is for information only – follow the manufacturer's instructions and applicable electrical installation rules when installing.

    Carlo Gavazzi EM21 72D – CT-operated three-phase meter with Modbus

    The Carlo Gavazzi EM21 72D AV5 3 X O S X is a CT-operated 5(6) A three-phase meter with RS485 Modbus RTU, pulse output and a detachable display for internal metering.

    Illustrative image may have been created using AI. The appearance of the product may differ slightly from the image shown. Please refer to the technical specification.

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