Power metering and monitoring

A measurement and monitoring unit is an electrical measurement and control device that continuously records the parameters of a circuit or installation: voltage, current, active and reactive power, power factor, frequency, energy and harmonics up to the 63rd order. Socomec's DIRIS A, DIRIS B ranges and the DIRIS Digiware system comply with the IEC 61557-12 standard and communicate via Modbus RS485, Modbus TCP or BACnet IP depending on the model.

Architecture and ranges of DIRIS measurement and monitoring units

Single-circuit and multi-circuit units for different monitoring levels

The DIRIS A and DIRIS B measurement units each cover a distinct scope. The DIRIS A range is intended for monitoring a single electrical circuit with local display of measurements. The DIRIS B range offers extended capabilities for simultaneously monitoring several outgoing circuits in the same panel. Our installation experience confirms that this duality allows the technical choice to be standardised on a single product family, regardless of panel complexity.

Modular DIRIS Digiware system for evolving installations

The DIRIS Digiware system is based on a modular architecture in which measurement modules are added according to needs. This flexibility is particularly relevant in data centres and tertiary buildings where load distribution changes frequently. Feedback from installers confirms that this approach avoids fully replacing the equipment during a panel extension.

Connection and integration of measurement and monitoring units

Connection to current transformers and the measurement network

Connection is made via current transformers (CTs) with a 1A or 5A input in series, and the voltages of phases L1, L2, L3, N as well as earth. This standard configuration ensures compatibility with existing modular devices. In the field, we find that this indirect measurement principle preserves operator safety while maintaining reading accuracy.

Multi-protocol communication for energy supervision

Modbus RS485, Modbus TCP and BACnet IP communication allow direct integration into a BMS (Building Management System) or an existing supervision system. Our standard practice favours Modbus TCP for new installations on an Ethernet network, and Modbus RS485 for extensions on existing serial infrastructure. The BACnet IP protocol makes interoperability easier in tertiary buildings already equipped with heating, ventilation and air-conditioning management systems.

Applications and installation contexts

Energy monitoring in data centres and critical buildings

Measurement and monitoring units are used in data centres, where detailed monitoring of consumption per rack or conditioned room is key to controlling operating costs. Our installation feedback shows that harmonic analysis up to the 63rd order helps diagnose disturbance generated by servers' switched-mode power supplies.

Energy efficiency and regulatory compliance in industry

In industrial buildings, the measurement and monitoring unit contributes to the energy audit required by regulations. Monitoring power factor and active and reactive energy helps optimise the setting of capacitor banks. We find that this feature significantly reduces reactive-power penalties billed by the energy supplier.

Frequently asked questions

What is the difference between a single-circuit and a multi-circuit measurement unit?

A single-circuit unit measures the parameters of a single electrical circuit, whereas a multi-circuit unit simultaneously monitors several circuits. The choice depends on the number of outgoing circuits to be instrumented in the low-voltage panel.

Can a DIRIS measurement unit replace a network analyser?

DIRIS units measure harmonics up to the 63rd order in line with the IEC 61557-12 standard, which covers many power-quality analysis needs. For advanced diagnostics including transients or voltage dips, a dedicated network analyser is still needed.

Which protocol should be chosen between Modbus and BACnet for an existing BMS?

Modbus RS485 or TCP suits electrical supervision systems, while BACnet IP fits naturally into multi-technical BMS platforms already building-oriented. The DIRIS measurement unit supports all three protocols depending on the model, preserving compatibility with the infrastructure in place.

Are 1A and 5A current transformers interchangeable on the same unit?

The measurement unit is configured for one CT rating or the other. Connecting a 5A CT to an input designed for 1A would distort the measurements. The model's technical documentation states the appropriate rating and the transformation ratio to configure.

Does the DIRIS Digiware system require a central module?

Yes, the Digiware architecture is based on a head module that aggregates data from the distributed measurement modules. This star topology simplifies wiring in large panels and makes later extensions easier without redoing the whole installation.