Energy meters

An energy meter is an electrical measuring device that quantifies the active energy consumed or produced on a single-phase or three-phase circuit. The Socomec COUNTIS E (E1x to E5x series) and Lettel ranges cover rated currents from 40 A to 6000 A depending on the connection mode, with a measurement accuracy of 0.5% and MID-certified versions for legal energy billing.

Connection principles and measurement ranges of the energy meter

Direct connection for low- to medium-power installations

Direct-connection energy meters integrate the measurement terminal block into the housing. Our installation feedback confirms that ratings available up to 40 A, 80 A or 100 A cover most tertiary distribution and small industrial panels. This mode simplifies wiring and reduces space in the electrical panel.

Connection via current transformers for high power

For high-power outgoing circuits, connection via CTs (current transformers) extends the measurement range up to 6000 A. The CT ratio is configured directly on the device's keypad, which our commissioning tests show is a significant time saving during on-site setup.

Communication and integration into supervision systems

Available protocols for remote reading and monitoring

Energy meters in the COUNTIS E range offer several communication interfaces depending on integration needs. Modbus RS485 remains the most widespread standard in industrial PLCs. M-Bus meets the requirements of multi-user metering applications. Ethernet TCP makes integration into existing IT networks easier. The pulse output allows simple collection by third-party metering equipment.

Interoperability with the Socomec measurement ecosystem

In the field, we find that full integration into the Socomec monitoring ecosystem, notably with DIRIS network analysers and the modular ISOM Digiware measurement solution, provides unified energy supervision. This consistency of protocols and data formats avoids conversion intermediaries and reduces setup errors.

Metrological certifications and regulatory compliance

MID certification for legal energy billing

The European MID (Measuring Instruments Directive) governs measuring instruments used for tariff purposes. MID-certified versions of energy meters guarantee metrological traceability and compliance for cost re-billing between co-owners, tenants or users. Our standard practice systematically favours these versions as soon as energy-cost distribution is envisaged.

Accuracy class and measurement reliability

The 0.5% accuracy class means the maximum permissible measurement error is half a percent of the value read. This performance meets design offices' requirements for consumption monitoring in data centres and critical infrastructure, where every kilowatt-hour matters in the energy balance.

Typical applications and choice of mounting mode

Sectors using energy meters

Applications recorded include manufacturing industry, public infrastructure, marinas for energy distribution to pontoons, multi-unit shopping centres, data centres for PUE (Power Usage Effectiveness), campsites with individual pitches, and electric-vehicle charging stations where accurate measurement determines billing.

DIN-rail or panel flush mounting

The polyamide housing allows two mounting modes depending on the electrical panel's architecture. DIN-rail mounting suits standard modular panels. The front-face version for panel mounting integrates into panel doors or supervision desks. Feedback from installers confirms that this finish choice often determines the decision at the panel design stage.

Frequently asked questions

What is the difference between an MID energy meter and a standard meter?

An MID-certified energy meter complies with European directive 2014/32/EU and allows legal billing of energy consumed. A standard meter offers the same measurement accuracy but cannot serve as a tariff basis in the event of a metrological dispute.

Can the CT ratio be configured without external software?

Yes, on the COUNTIS E and Lettel ranges, the current transformer ratio is programmed directly on the energy meter's keypad. This feature removes the need for a laptop on site during commissioning.

Which communication protocol should be chosen for a new tertiary building?

Modbus RS485 remains the most universal choice for integration into a PLC or a building management system. Ethernet TCP is preferred when the energy meter needs to integrate directly into the existing IT network without a conversion gateway.

Is direct connection up to 100 A sufficient for an electric-vehicle charging station?

For an individual 22 kW three-phase charging station, the rated current is around 32 A. Direct connection up to 100 A comfortably covers this need. For multiple charging hubs or main distribution outgoing circuits, connection via CTs becomes necessary.