Carlo GavazziEM330-DIN.AV5.3.H.M1.PF.AThree-Phase DIN-Rail Energy Meter, 400-480 V L-L, 5(6) A CT Input, 100-240 V AC/DC Aux Supply, M-Bus, MID Class B

Product Description

What this part is

A Carlo Gavazzi EM330 three-phase energy meter in a 3-module DIN-rail housing. Unlike the direct-connect EM340, this one measures current through external 5 A current transformers, so it sizes to whatever the CT ratio is rather than to a 65 A limit. Backlit LCD with three rows of eight digits, three touch keys, per-phase as well as system readings, and an M-Bus port for remote reading.

Decoding the order code

Read EM330-DIN.AV5.3.H.M1.PF.A left to right as model, range, system, power supply, output, option, measurement.

EM330-DIN – three-phase meter, DIN-rail housing, 3 modules, CT inputAV5 – 400 to 480 V L-L AC (230 to 277 V L-N), 5(6) A via CT3 – 3-phase, 3- or 4-wire (the non-certified X version also does 2-phase 3-wire and 1-phase 2-wire)H – auxiliary power supply, 100 to 240 V AC/DC ±10%M1 – M-Bus communication port (S1 would be RS485 Modbus, O1 a pulse output)PF – certified to the MID Directive, Modules B and D, usable for fiscal metrologyA – power is always integrated in both directions and that total register is the MID-certified one

What these specs mean in practice

Two things separate this from the more common EM340. First, it is CT-connected: the 5(6) A rating is the secondary current, not the load, and you must supply three 5 A-secondary current transformers and program the CT ratio into the meter. Nothing is metered until that ratio is set. Second, the H suffix means it is not self powered — a 100 to 240 V AC/DC auxiliary supply has to be wired to its own terminals, which is an advantage on a 480 V system where you would not want the meter to draw from the measured phases. Maximum CT x VT product is 1000. The A measurement option totalises regardless of current direction, so it will not separate import from export.

Published specifications

System: 3-phase, 3- or 4-wire, CT connectionNominal voltage: 400 to 480 V L-L AC (230 to 277 V L-N)Current: In 5 A, Imax 6 A, Imin 0.25 A via CT; max CT x VT = 1000Auxiliary supply: 100 to 240 V AC/DC ±10%, ≤1 W / ≤8 VAStart-up current: 10 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%); frequency ±0.2%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 phaseExtras: run-hour meter, calculated neutral current, phase-sequence and wrong-connection detectionCommunication: M-Bus per EN13757-1, 0.3 / 2.4 / 9.6 kbaud, up to 250 meters, ID range 9000 0000 to 9999 9999Digital input: 1, volt-free contact, for tariff switchingSampling: 4096 samples/sInsulation: 4000 V AC RMS for 1 minute; overvoltage category IIIOperating temperature: −25 to +55 °C (PF option)Protection: IP51 front, IP20 terminals; tamper-proof sealing covers included, two seal pointsHousing: 54 x 90 x 63 mm (W x H x D), 3 DIN modules, self-extinguishing polycarbonateVoltage input terminals: 1 to 4 mm², 0.6 Nm; other terminals 1.5 mm², 0.4 NmApprovals: CE, MID (PF only), cULus to UL61010-1Weight: approx. 240 g

Quantity and configuration

Sold as 1 piece — the meter only. Current transformers are not included and are required; so is the auxiliary supply wiring. Sealing covers are part of the standard product; confirm what is present before relying on them for a revenue installation.

Installation and setup notes

Set the CT ratio (page P4) and, if voltage transformers are used, the VT ratio (P5) before commissioning — readings scale off those two numbers and the front LED pulse weight is derived from their product. On M1 units also set the M-Bus primary address (P13, 1 to 250) and baud rate (P15, default 2.4 kbaud). The built-in wrong-connection check flags reversed CTs and out-of-order phases, but it only works on loads with PF above 0.766 inductive or 0.996 capacitive and at least 10% of rated primary current. Menus are password protected, default 0000; Measurement and Home-page menus are locked on PF units.

Interchange guidance

The EM330 and EM340 look alike and are not interchangeable: the EM340 is direct-connect 5(65) A at 208 to 400 V L-L and self powered, while this EM330 needs CTs and a separate auxiliary supply. Within the EM330 range, S1 and O1 replace the M-Bus port with RS485 Modbus or a pulse output, and the .PF.B version separates imported from exported energy. The ET330 is the transducer version with no display. Treat all of those as related models rather than equivalents.