Energy Meters 101: How to Choose the Right kWh Meter for Your Project

Energy meters measure electrical consumption in kilowatt-hours, forming the basis for billing, monitoring and energy management. Choosing the right one depends on the supply type and how the data will be used.

Single-phase vs three-phase

Residential and small commercial installations usually use single-phase meters, while larger buildings and industrial sites need three-phase meters to measure a three-phase supply accurately.

Direct-connected vs CT-connected

• Direct-connected – wired straight into the circuit, typically up to 100A.
• CT-connected – uses current transformers for higher currents, scaling the measurement safely.

Accuracy class and communication

For billing, look for Class 1 or Class 0.5 accuracy. For building management and remote reading, choose meters with RS485 Modbus RTU or pulse output so the data can feed a monitoring system.

DIN-rail mounting

Walax energy meters are DIN-rail mountable for fast installation inside distribution boards, with backlit LCD displays for easy on-site reading.