Single-circuit metering

A single-circuit measurement unit is an electrical measurement and monitoring device dedicated to a single circuit. The DIRIS A-10, A-20, A-30 and A-40 models work with current transformers (CTs) with a 1A or 5A input and feature a standard Modbus RS485 link for supervision integration. The IEC 61557-12 standard governs their metrological performance and safety requirements.

Connection principle and CT input safety

Connection via current transformers and mandatory precautions

Measurement inputs are made via 1A or 5A CTs mounted in series on the monitored circuit. Short-circuiting the CT secondaries is mandatory whenever the unit is disconnected. This operation preserves personal safety and prevents the transformers from being destroyed by secondary overvoltage. Our standard practice favours using a dedicated Socomec PTI module that automates this protection and reduces the risk of error during intervention.

Voltage inputs and network compatibility

The L1/L2/L3/N voltage inputs allow measurement of three-phase-with-neutral network parameters. This configuration covers most low-voltage installations in tertiary buildings and critical infrastructure. In the field, we find that the systematic presence of the neutral input makes it easier to diagnose imbalances and insulation faults.

Communication and integration into energy supervision

RS485 serial link and Modbus TCP Ethernet option

The RS485 Modbus link is available as standard across the whole range. Depending on the model, a Modbus TCP option allows direct integration onto an Ethernet network without an additional converter. Feedback from installers confirms that this flexibility significantly reduces wiring time in panels already fitted with IP infrastructure.

Remote operation via supervision software

Data collected can be accessed remotely via Socomec's supervision software. This centralisation provides a consolidated view of consumption and power-quality indicators. Our installation experience shows that this approach is particularly effective for tracking energy-performance contracts and regulatory reporting.

Modularity and evolution of the DIRIS A-30 and A-41 units

Expansion slots and functional adaptation

The DIRIS A-30 and DIRIS A-41 models feature modular expansion slots. The DIRIS A-30 accepts up to 4 additional modules, while the DIRIS A-41 accommodates 3. This modularity allows digital inputs, relay outputs or communication interfaces to be added after the initial installation.

Range choice according to the required monitoring level

The DIRIS A-10 and A-20 cover standard measurement needs with no expansion. The A-30 and A-41 suit evolving installations or critical outgoing circuits requiring additional signalling or control functions. Our installation feedback shows that this segmentation avoids initial over-specification while securing the system's future scalability.

Typical applications and installation contexts

Targeted monitoring in constrained environments

The single-circuit measurement unit is used to monitor a single electrical circuit: a panel's main outgoing circuit, the supply to a secondary panel, or a line dedicated to sensitive equipment. Data centres use these devices for granular monitoring of server racks. Tertiary buildings deploy them on heating, ventilation or lighting outgoing circuits as part of energy-efficiency initiatives.

Electrical panel integration and mechanical constraints

The polyamide housing and door mounting make integration into an electrical panel easier. This design withstands the environmental conditions found in technical rooms or electrical rooms. We find that this type of fixing allows direct access to screens and indicators without fully opening the panel, reducing operating and maintenance time.

Frequently asked questions

Why is short-circuiting the CT secondaries mandatory when disconnecting?

A CT with an open secondary generates extremely dangerous overvoltages that can reach several kilovolts. Short-circuiting protects people and equipment. The dedicated Socomec PTI module carries out this operation automatically and safely.

What is the difference between the standard RS485 link and the Modbus TCP option?

The RS485 Modbus link requires dedicated serial wiring and possibly a converter for network integration. The Modbus TCP option allows a direct connection to existing Ethernet infrastructure, simplifying the communication architecture in modern installations.

How should you choose between DIRIS A-10, A-20, A-30 and A-41 for a project?

The A-10 and A-20 suit fixed measurement needs with no foreseeable expansion. The A-30 and A-41 are justified whenever additional functions or future evolution are anticipated, thanks to their modular expansion slots.

Can a single-circuit measurement unit be used for multi-site supervision?

Yes, via Socomec's supervision software and the RS485 or Modbus TCP link. Data from each site is sent up to a centralised platform for analysis and consolidated reporting, meeting the needs of operators managing extensive property portfolios.

Which standard guarantees the reliability of the DIRIS A unit's measurements?

Compliance with the IEC 61557-12 standard ensures that metrological performance, accuracy classes and type tests meet international requirements for low-voltage electrical parameter measurement equipment.