What is Electrical Submetering?
Electrical submetering refers to the practice of installing additional meters downstream of the main utility meter to measure electricity consumption in specific areas, departments, or individual equipment within a facility. It enables detailed monitoring and allocation of energy use across different circuits, tenants, or processes.
Unlike the main billing meter provided by utilities, which measures the total energy entering a facility, submeters provide granular visibility into internal energy distribution. Submetering systems are widely adopted in commercial buildings, factories, data centers, and multi-tenant properties to achieve energy efficiency, cost transparency, and load optimization.
How Does Electric Submetering Work?
Electrical submeters operate by measuring voltage and current at selected distribution points and computing parameters such as active power (kW), reactive power (kvar), apparent power (kVA), and energy consumption (kWh).
Each submeter connects to current transformers (CTs) or Rogowski coils that capture current signals without interrupting power. The meter’s internal processor multiplies voltage and current vectors, applying power factor and harmonic correction algorithms to ensure accuracy.
Modern submeters integrate with communication networks such as Modbus RTU/TCP, BACnet, M-Bus, LoRa, or Wi-Fi, allowing real-time data collection and integration into Building Energy Management Systems (BEMS) or SCADA platforms. Through digital communication, facility managers can view detailed consumption reports, set alarms, and even implement automated energy-saving control strategies.
What are the Benefits of Electrical Submetering?
- Accurate Cost Allocation – Enables fair billing in multi-tenant buildings or shared industrial facilities by assigning actual energy costs to each user or process.
- Energy Efficiency – Identifies inefficiencies, standby loads, and power factor issues for targeted optimization.
- Preventive Maintenance – Detects abnormal consumption patterns that may indicate equipment degradation or faults.
- Load Management – Helps prevent overloads and improves system balance by analyzing phase currents and harmonics.
- Regulatory Compliance – Facilitates data logging for energy audits and sustainability reporting (ISO 50001, LEED, BREEAM).
- Integration with Renewable Systems – Supports PV or battery systems for optimizing self-consumption and demand response strategies.
What are the Types of Electrical Submeters?
Electricity submetering equipment can be classified according to different characteristics, mainly including three dimensions: number of monitoring channels, brands, and typical application scenarios.
1. Classification by Number of Monitoring Channels
Single-Circuit Meters: Suitable for monitoring the power of a single device or branch, such as air conditioning, heat pump, or lighting circuits. These meters are typically mounted on a DIN rail, featuring a compact design and standard Modbus communication capabilities.
Multi-Circuit Meters: Can monitor multiple three-phase or single-phase circuits simultaneously.
2. Classification by Brands
Different brands have developed their own technical characteristics and application positioning in the field of submetering.
Schneider Electric provides complete solutions from basic metering to high-end energy analysis, with typical series including the iEM3000 and PM5000/8000 series. Features: Industrial-grade reliability, support for EcoStruxure platform integration.
Siemens‘ flagship product, the 7KM PAC series, balances high accuracy with power quality analysis capabilities and is widely used in industrial facilities and data centers.
Carlo Gavazzi / Socomec / Leviton focus on commercial buildings and energy management, supporting multiple protocols such as BACnet, Modbus TCP, and M-Bus for easy building system integration.
3. Classification by Application Scenarios
Commercial Applications: Used in office buildings, shopping malls, hospitals, etc., for tenant billing, lighting, and air conditioning energy consumption monitoring.
Residential Applications: Suitable for apartment buildings, dormitories, and villa areas, for individual metering and smart home energy management.
Industrial Applications: Used for energy consumption analysis and energy efficiency optimization in production lines, electromechanical equipment, compressors, pump stations, etc.
Where to Use Electrical Submetering
Electrical submetering is applicable across various domains:
| Sector | Typical Application | Measurement Target |
| Commercial Buildings | Office towers, malls, hospitals | Tenants, HVAC, lighting |
| Industrial Plants | Production lines, workshops | Motors, compressors, ovens |
| Residential Complexes | Apartments, dormitories | Unit-level energy use |
| Data Centers | Server racks, PDU panels | IT loads, cooling systems |
| Renewable Energy Systems | PV + storage + load hybrid systems | Consumption vs generation |
Difference Between Electrical Submetering and Multifunction Meter
1.Definition differences
Ordinary Multifunction Meter: A multifunction meter is an intelligent instrument that comprehensively measures electrical parameters of a single circuit (single-phase or three-phase). It can measure various electrical parameters such as voltage, current, active power, reactive power, power factor, frequency, and energy, and uploads data via RS485/Modbus communication. It is commonly used in distribution cabinets, power monitoring systems, and energy management systems.
Multi-circuit Meter: A multi-circuit meter integrates multiple measurement channels in a single instrument, enabling simultaneous monitoring of multiple branches (e.g., 4, 6, 12, or even 36 circuits). It typically has multi-channel current input interfaces (via external multiple current transformers) and a shared voltage reference input terminal, allowing for centralized metering and monitoring of multiple load branches.
2.Functional Differences
Measurement Scope
Multifunction Meter: Primarily designed for high-accuracy measurement of a single circuit, suitable for main feeder metering or critical load monitoring.
Multi-Circuit Meter: Capable of simultaneously monitoring current, voltage, energy, and power data across multiple branch circuits, ideal for branch-level energy monitoring and load balance analysis.
3.Data Acquisition & Communication
Multifunction Meter: Communicates with upper systems via Modbus RTU/TCP, BACnet, or M-Bus, with one device per address.
Multi-Circuit Meter: Utilizes centralized communication design, where multiple circuits share the same communication address, enabling centralized data collection and batch upload, reducing wiring and communication costs.
4.Installation & Wiring
Multifunction Meter: Installed in main distribution circuits with relatively simple wiring.
Multi-Circuit Meter: Monitors multiple branch circuits using several CTs or multi-core current harnesses; overall, it saves space and wiring costs compared to multiple individual meters.
5.Application Level
Multifunction Meter: Used for main-level (Main Meter) or sub-level (Sub Meter) energy monitoring.
Multi-Circuit Meter: Applied at branch-level monitoring (Branch Level), such as in data centers (IDC), building energy submetering, lighting, and socket circuit monitoring.
Comparison of structure and measurement channels
| Item | Multifunction Meter | Multi-Circuit Meter |
| Measurement Channels | Single circuit (single-phase or three-phase) | Multiple circuits (typically 4–36 channels) |
| Voltage Input | One set of voltage inputs (3P+N) | Shared voltage input with a unified reference |
| Current Input | 1–3 current channels | Multiple current channels (each with an independent CT) |
| Typical Installation Location | Main incoming line or major branch circuits | Multiple branch circuits, racks, lighting, HVAC, or IT cabinet branches |
| Physical Structure | Panel-mounted or DIN-rail type | Usually modular DIN-rail or centralized wiring design |
How to Choose the Right electrical submeter?
Number of Monitoring Channels: Select a single-circuit, 3-circuit, 6-circuit, 12-circuit, or 24-circuit meter based on the number of monitoring branches;
Current Input Type: Select based on site conditions: direct measurement type (≤100A), external CT type (1A/5A or 333mV output), Rogowski coil input (flexible installation, suitable for high-density power distribution systems);
Communication Network: Confirm compatibility with the management system (RS485 Modbus RTU/TCP, BACnet, M-Bus, LoRa, Wi-Fi, 4G, etc.);
Accuracy and Certification: Select Class 0.5S/1.0 (IEC 62053-22/21) or metering-grade equipment with MID and ANSI certifications according to the application;
Revenue-grade Metering Platform: If used for billing, choose products with high-precision certification, traceability calibration, and tamper-proof functions;
System Integration Capability: Products that support open protocols and cloud platform access are preferred to facilitate unified energy consumption data management.
Conclusion
Sub-metering of electricity is a core component of modern energy management systems. By providing detailed monitoring of total energy consumption, it helps users accurately understand their energy consumption structure, achieving energy conservation, cost reduction, and transparent management.
Choosing the right sub-metering product—whether single-circuit or multi-circuit, stand-alone or networked—can enable businesses or buildings to take a crucial step towards improved energy efficiency, intelligent operation, and sustainable development.
