How to Choose an Electricity Meter

I. Core Selection Parameters

* Number of Power Supply Phases

* Single-phase electricity meters: Suitable for 220V power supply scenarios, such as residential buildings, apartments, and small shops. Simple wiring and high cost-effectiveness.

* Three-phase electricity meters: Suitable for 380V power supply scenarios, such as factories, large commercial buildings, and high-power industrial equipment. Misuse in residential settings is strictly prohibited.

* Current Specifications

* Labeled in Ib(Imax), where Ib is the reference current and Imax is the maximum rated current.

* Calculation Formula: Power P = Voltage U × Current I.

Small apartments: 5 (20) A, 10 (40) A

Medium apartments: 10 (40) A, 5 (60) A for high-power appliances

Large apartments: 15 (60) A, 30 (100) A

Industrial scenarios: Calculate based on total power and reserve redundancy to avoid overload.

Note: Current specifications should not be too high. Under small loads, high current meters have reduced metering sensitivity and are prone to metering deviation.

Accuracy levels:

1.0 level: Metering error ±1%, meets civilian metering needs, and is the first choice for households.

0.5S level: Metering error ±0.5%, high-precision metering, suitable for industrial and commercial settlement and energy efficiency monitoring.

2.0 level: Error ±2%, low metering accuracy, to be phased out gradually.

II. Scenario-based selection scheme

Residential/Rental housing: Single-phase smart energy meter, supports remote meter reading, prepayment, and remote control, facilitating electricity management and arrears control. Factory/Office Building: Three-phase multi-functional energy meter with electrical parameter measurement, harmonic analysis, and energy consumption statistics functions, compatible with energy management systems.

Photovoltaic/Charging Pile: Bidirectional smart energy meter, enabling forward and reverse energy metering, meeting grid-connected metering and time-of-use pricing requirements.

Remote/Rural Areas: Wide voltage range single-phase meter, supporting LoRa/NB-IoT communication, strong anti-interference capability, reducing operation and maintenance costs.

III. Selection and Usage Prohibitions

The energy meter current specification must match the incoming line conductor to avoid overload and overheating, which could lead to safety hazards.

Must possess a CMC metering instrument production license and a CPA type approval certificate. The equipment connected to the power supply department must meet the State Grid/Southern Power Grid access requirements.

Unauthorized disassembly and replacement of the energy meter is strictly prohibited. Expansion or replacement requires application to the power supply department.

Select the communication method (RS485, NB-IoT, 4G, etc.) according to the installation environment to ensure stable data transmission.

Scheduled replacement: Mechanical meters should not be used for more than 8 years, and smart meters for more than 10 years. Exceeding these periods will lead to a decrease in accuracy.

IV. Summary

The selection of electricity meters should be based on the principles of safety and reliability, accurate metering, and suitability for different scenarios. Reasonable matching of phase number, current, accuracy, and communication functions can effectively mitigate electricity consumption risks, ensure fair metering, and support refined energy consumption management.