Carlo GavazziEM340-DIN.AV2.3.X.S1.XThree-Phase DIN-Rail Energy Meter, 208-400 V L-L, 5(65) A Direct Connection, RS485 Modbus, Self Powered

Product Description

What this part is

A Carlo Gavazzi EM340 three-phase energy meter in a 3-module DIN-rail housing. Load current passes directly through the meter up to 65 A, so no current transformers are required, and it powers itself from the measured phases. Backlit LCD with three rows of eight digits and three touch keys, RS485 Modbus RTU for data collection, and both system-level and per-phase readings including kWh per phase.

Decoding the order code

Read EM340-DIN.AV2.3.X.S1.X left to right as model, range, system, power supply, output, option.

EM340-DIN – three-phase meter, DIN-rail housing, 3 modules, direct connectionAV2 – 208 to 400 V L-L AC, 5(65) A direct connection3 – 3-phase 3- or 4-wire, also 2-phase 3-wireX – self powered from the measured voltage, −20% +20%, 45 to 65 HzS1 – RS485 Modbus RTU port (M1 would be M-Bus, O1 a pulse output)X – standard version, not MID certified and not usable for fiscal or legal metrology

What these specs mean in practice

The final X is the one buyers get wrong. This is the standard, non-certified EM340: it measures to Class 1 / Class B accuracy but carries no MID certification, so it is fine for cost allocation, monitoring and energy management and not acceptable where a legally billable meter is required — that is the PF version. In exchange, the X version unlocks the Measurement and Home-page menus, so you can choose between A mode (both directions summed) and B mode (imported and exported energy on separate registers) in the field, and pick which page the meter shows at power-up. Direct 65 A connection means 2.5 to 16 mm² conductors land on the meter itself; above 65 A you need the CT-connected EM330 instead.

Published specifications

System: 3-phase 3- or 4-wire, 2-phase 3-wire; direct connectionNominal voltage: 208 to 400 V L-L AC (113 to 265 V L-N range), −20% +20%, 45 to 65 HzCurrent: Ib 5 A, Imax 65 A, Imin 0.25 A, direct connectionStart-up current: 20 mA; start-up voltage 90 V L-NActive energy: Class 1 per EN62053-21, Class B per EN50470-3Reactive energy: Class 2 per EN62053-23Current/voltage accuracy: ±0.5% of reading (L-L voltage ±1%)Active power accuracy: ±1% of reading; reactive power ±2%System values: kW, kvar, kVA, V L-L, V L-N, PF, Hz, kW demand and demand peakPhase values: kW, kvar, kVA, V L-L, V L-N, A, PF, plus kWh per phaseRegisters: kWh and kvarh imported/exported, kWh+ on two tariffsCommunication: RS485 Modbus RTU slave, 9.6 / 19.2 / 38.4 / 57.6 / 115.2 kbaud, address 1 to 247, up to 247 devices per bus, 1 s refresh, Rx/Tx shown on displayDigital input: 1, volt-free contact, for tariff switchingFront LED: 1000 imp/kWhSampling: 4096 samples/sCurrent withstand: 1950 A for 10 ms; short-circuit withstand 4.5 kA / 10 ms per IEC62052-31:2015Insulation: 4000 V AC RMS for 1 minute; overvoltage category III, utilisation category UC2Operating temperature: −25 to +65 °C (X option), indoorProtection: IP51 front, IP20 terminalsHousing: 54 x 90 x 63 mm (W x H x D), 3 DIN modules, Noryl self-extinguishing UL 94 V-0Measuring terminals: 2.5 to 16 mm², 2.8 Nm; other terminals 1.5 mm², 0.4 NmPower consumption: ≤1 W, ≤10 VAWeight: approx. 240 g

Quantity and configuration

Sold as 1 piece. No current transformers, auxiliary supply or communication accessories are needed or included — the meter is self powered and connects directly.

Installation and setup notes

Set the system type (page P3) to match the actual wiring, 3-wire or 4-wire, before trusting any reading. The Install page (P7) enables a wrong-connection check that flags reversed current direction and out-of-order phases; it needs at least 10% of rated current and a load PF above 0.766 inductive to give a verdict, and can be switched off. On this S1 version set the Modbus address (P14), baud rate (P15), parity and stop bit (P16) — unique address per device, and terminate the RS485 line only at the last device by linking A− to T. Runs beyond 1000 m need a repeater. Energy is totalised per measuring interval by summing positive phase energies into kWh+ and negative into kWh−, so mixed-sign phases do not cancel.

Interchange guidance

The suffixes define the part. EM340-DIN.AV2.3.X.S1.PF.A or .PF.B are the MID-certified versions and are what you need for billing — this one is not. M1 and O1 replace RS485 with M-Bus or a pulse output. The EM330 is the CT-connected 400 to 480 V model with an auxiliary supply and is not a substitute; the ET340 is the transducer version without a display; the 1- and 2-DIN EM111 and EM112 are single-phase. Related models in the same range, not drop-in equivalents.