EEM-MA770-24DC - Meter

EEM-MA770-24DC differs from the standard EEM-MA770 primarily in the way the device is powered.

The meter is designed for a nominal supply voltage of 24 V DC, and the permissible supply voltage range is from 18 up to 30 V DC.

This allows the device to be powered directly from a typical 24 V DC power supply used in automation cabinets together with PLCs, I/O modules and other industrial devices.

EEM-MA770-24DC can operate in three-phase 3- and 4-wire, two-phase and single-phase networks.

All measurement channels operate simultaneously, and the device uses continuous true root mean square True RMS.

The fundamental frequency range is from 45 to 65 Hz, making the meter suitable for both 50 Hz and 60 Hz installations.

The meter has three voltage inputs V1, V2 and V3 enabling simultaneous monitoring of individual phase parameters.

The direct measurement range is 18–690 V AC phase-to-phase and 11–400 V AC phase-to-neutral.

For higher-voltage installations, external voltage transformers can be used.

EEM-MA770-24DC has three current measurement channels I1, I2 and I3 designed for use with conventional current transformers.

Transformers with secondary current are supported 1 A and 5 A, and the configurable primary-side current can range from 1 to 20 000 A.

Current measurement accuracy is 0.2%, enabling the device to be used for both energy consumption monitoring and analysis of individual circuit loads.

The power measurement accuracy of EEM-MA770-24DC is 0.5%.

Active energy measurement meets the requirements class 0.5 S according to IEC 62053-22 and ANSI C12.20.

Reactive energy is measured in class 2 according to IEC 62053-23.

EEM-MA770-24DC enables analysis of higher voltage and current harmonics up to the 63rd harmonic.

This function helps detect waveform distortions caused by inverters, variable-speed drives, switched-mode power supplies and other nonlinear loads.

The sampling frequency is 12.8 kHz for 50 Hz networks and 15.36 kHz for 60 Hz networks.

The integrated RJ45 Ethernet port enables communication at 10 or 100 Mb/s.

Modbus TCP enables measurement values to be transmitted directly to PLCs, SCADA systems, BMS and energy management systems.

The device also supports REST API, and current EMpro device firmware also provides MQTT, enabling easier data transmission to modern IIoT systems and IT platforms.

The data logging function enables selected parameters to be recorded without continuous polling of the meter by the higher-level system.

For a typical configuration, it is possible to record up to 8 parameters for more than 90 days at a 15-minute logging interval.

The data can be used to analyze energy consumption, identify load trends and compare installation operation over different periods.

The meter has one digital input compliant with IEC/EN 61131-2 Type 3.

The input operates at 24 V DC and can be used, among other purposes, to handle additional signals and device functions.

A configurable 24 V DC solid-state output is also available with a maximum current of 100 mA.

EEM-MA770-24DC has a backlit, two-color, multi-line LCD display enabling local viewing of measurement parameters.

The integrated web server allows the meter to be configured using a standard web browser.

A guided step-by-step installation wizard simplifies configuration of network type, measurement inputs and communication and speeds up initial device commissioning.

EEM-MA770-24DC is designed for installation in the front panel of a distribution board or control cabinet.

The device front dimensions are 96 × 96 mm, the total depth is approximately 73.3 mm, and the required installation depth is approximately 58.3 mm.

The enclosure has an IP20 protection rating, while the display section with the supplied gasket fitted achieves IP54.