Compact MID-compliant energy meter from Carlo Gavazzi

The EM24 energy meter from Carlo Gavazzi provides complete utility metering for load analysis, offering conventional three-phase active and reactive energy measurements, together with gas, hot and cold water and remote heating consumption. The meter conforms to the EU Measuring Instruments Directive (MID); it also meets Class 1 European accuracy standards EN62053-21 as well as EN50470-3 (Class B).

A tamper-proof terminal cover protects all inputs and outputs when used for cost allocation purposes. In applications such as shopping malls, apartments, public buildings and industrial premises, the new analyser allows cost splitting and variable control, thanks to its two digital outputs and RS485 communication port. These technical features provide a quick and easy data transmission to PC/PLC alarm, monitoring and control systems.

Where such standard communication links are unsuitable because of EMC disturbances or excessive transmission distances, utility metering systems can nevertheless be established using Dupline®’s specific features.

Dupline adds the capability to transmit multiple digital and analogue signals over several kilometres via an ordinary two-wire cable. Modular design and simple operation enable even novices to implement it in new or existing applications. Solutions are constructed by combining products from a broad range of available Dupline modules, including digital and analogue I/O, PLC and PC interfaces, human-machine interfaces and modems.

Typically used as a remote I/O system, Dupline® creates a link between the energy meter and other field devices such as sensors, contactors, valves and pushbuttons via a central Monitoring Controller, which may be a PLC, PC or the Dupline Controller.

Dupline can also be used as a simple wire-replacement system where signals are transmitted peer-to-peer without involving controllers. As well as copper wire, signals can be carried on fibre optic cable, via radio modem, on leased telephone lines or via GSM Modem.

Fieldbus functions are integrated into the existing power analyser circuitry, housed in a compact 90 x 71 x 65mm standalone module. The EM24 features a large LCD screen, which uses STN technology to ensure sharp readability over a wide angle. Its front panel uses a programmable four-position rotary selector to switch between alternative measurement pages, and incorporates a joystick to quickly scroll through the readout.

As well as tamper-proof facilities and password protection, a physical seal gives access to the meter's application-oriented programming structure, which enables programmers to quickly set the meter up by choosing between eight pre-set programmes: basic, advanced, multi domestic, shopping centres, solar energy and light industrial applications.

The EM24 is designed to be DIN rail mounted and, at only four DIN modules wide, is ideal for sub metering applications where multiple meters need to be installed. The EM24 provides the installer with time and cost savings, and features an application-oriented programming mode and connection system to simplify installation.