Milesight CT103 LoRaWAN 250A Smart Current Transformer (EU868)

The Milesight CT103 is an advanced LoRaWAN Smart Current Transformer designed for wireless electrical current monitoring in commercial buildings, industrial facilities, electrical distribution panels and energy management applications.

With a rated measurement capacity of 250A RMS, the CT103 enables reliable monitoring of medium-to-high electrical loads, making it particularly suitable for commercial HVAC systems, industrial compressors, electrical distribution circuits and machinery.

The device features an innovative split-core current transformer design, allowing installation around an existing electrical conductor without cutting or disconnecting the cable.

This non-invasive installation method makes the CT103 an excellent solution for retrofitting existing electrical installations with wireless monitoring capabilities while minimizing installation complexity.

Unlike multi-channel monitoring systems, the CT103 is designed for single-channel current measurement, providing detailed monitoring of one selected electrical conductor or circuit.

The device measures RMS electrical current with a 3.3 kHz sampling frequency, enabling accurate monitoring of changing electrical loads and equipment operating conditions.

It provides ±1% measurement accuracy for currents above 5A RMS and ±3% accuracy for currents up to 5A RMS, with a measurement resolution of 1 mA.

In addition to RMS current measurements, the CT103 supports accumulated ampere-hour (Ah) reporting, allowing users to monitor current usage trends and equipment operating patterns over time.

The device can also provide calculated electrical energy consumption in kWh when the nominal voltage and power factor are configured. These values are estimates derived from current measurements and configured parameters rather than direct voltage and power measurements.

One of the CT103's most important advantages is its battery-free, self-powered design.

The device harvests energy inductively from the monitored conductor, reducing maintenance requirements and eliminating the need for regular battery replacement.

According to the manufacturer's current specifications, self-powered reporting requires approximately 3A for a 1-minute reporting interval or 2.8A for a 10-minute reporting interval.

For applications involving lower current levels, the CT103 also supports external 5V power through USB Type-C, enabling operation when induced energy is insufficient.

The CT103 communicates using LoRaWAN EU868, allowing long-range wireless transmission of measurement data to compatible LoRaWAN gateways and network servers.

It supports LoRaWAN Class A operation, together with OTAA and ABP activation, making it suitable for integration into standard LoRaWAN infrastructures and compatible IoT monitoring platforms.

The CT103 provides configurable current threshold alarms and overrange alarms, helping detect abnormal electrical loads, unexpected equipment operation and potentially overloaded circuits.

The device also supports an external NTC temperature sensor, enabling cable temperature monitoring over a range of −20°C to +100°C.

Its compact 16 mm conductor opening and detachable transceiver design make it suitable for installation in crowded electrical panels and technical enclosures.

The wireless transceiver can be positioned separately from the current transformer using a compatible extension cable, helping improve installation flexibility and LoRaWAN signal reception.

Configuration is supported through USB Type-C and LoRaWAN downlink commands, while Firmware Update Over the Air (FUOTA) helps simplify maintenance.

The device also includes an LED status and alarm indicator, providing visual information about operating conditions.

With an IP30 protection rating, the CT103 is intended for protected indoor electrical installations and technical environments.

The Milesight CT103 is suitable for commercial electrical load monitoring, HVAC systems, compressors, industrial machinery, pumping stations, electrical distribution boards and predictive maintenance applications.

By combining 250A current measurement, non-invasive installation, battery-free operation and long-range LoRaWAN communication, the CT103 provides an efficient solution for modern electrical monitoring and Industrial IoT deployments.

Important: The CT103 directly measures RMS current (A) and accumulated current (Ah). Calculated kWh values depend on configured voltage and power factor and should not be considered certified or billing-grade energy measurements. For accurate electrical energy metering, a dedicated energy meter should be used.

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🔑 Key Features

⚡ 250A RMS Current Measurement – Measures electrical current up to 250A on one monitored conductor.

🔌 Single Measurement Channel – Dedicated monitoring of one electrical circuit or phase.

📡 LoRaWAN EU868 Connectivity – Long-range wireless communication for compatible European IoT networks.

🔋 Battery-Free Operation – Self-powered through energy induced from the monitored conductor.

🔌 Optional 5V USB-C Power – External power supply for low-current applications.

🧲 Split-Core Clamp Design – Non-invasive installation around existing electrical conductors.

🎯 High Measurement Accuracy – ±1% above 5A RMS and ±3% at or below 5A RMS.

📊 3.3 kHz Sampling Frequency – High-frequency sampling for accurate RMS current monitoring.

📈 Accumulated Current Monitoring – Supports ampere-hour (Ah) reporting.

⚡ Calculated kWh Reporting – Estimates energy consumption using configured voltage and power factor.

🔔 Current Threshold Alarms – Detect unusual current levels and equipment operating conditions.

🚨 Overrange Alarms – Identify currents exceeding the supported measurement range.

🌡️ NTC Temperature Sensor Support – Optional monitoring of cable temperature from −20°C to +100°C.

📏 16 mm Conductor Opening – Compact clamp design for restricted electrical panel spaces.

🔧 Detachable Transceiver – Flexible placement of the communication module.

⚙️ Remote Configuration – Configure supported parameters through LoRaWAN downlinks.

🔄 FUOTA Support – Firmware updates over the air.

📶 LoRaWAN Class A / OTAA / ABP – Standard LoRaWAN network compatibility.

💡 LED Status Indicator – Visual indication of device operation and alarm conditions.

🛡️ IP30 Protection – Suitable for protected indoor electrical installations.

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🛠 Applications

🏢 Commercial Building Monitoring – Monitor medium-to-high electrical loads in commercial facilities.

❄️ Commercial HVAC Systems – Monitor electrical current drawn by air-conditioning and ventilation equipment.

🧊 Chillers & Refrigeration Equipment – Track operating current and detect abnormal load conditions.

🏭 Industrial Machinery – Monitor electrical loads of manufacturing and production equipment.

⚙️ Industrial Compressors – Detect operating status and unexpected current variations.

💧 Pumping Stations – Monitor pump operation, overload conditions and unexpected shutdowns.

⚡ Electrical Distribution Panels – Add wireless current monitoring to existing electrical circuits.

🏗️ Manufacturing Facilities – Collect electrical load data from selected production equipment.

🔧 Predictive Maintenance – Identify abnormal current patterns that may indicate developing faults.

📊 Electrical Load Analysis – Evaluate current trends and estimated energy usage.

📡 Industrial IoT Systems – Integrate electrical current data into remote monitoring platforms.

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📦 Package Includes

According to the manufacturer's CT10x documentation, the standard package is expected to include:

• 1 × Milesight CT103 Smart Current Transformer with 250A split-core clamp

• 1 × USB-C NTC Temperature Sensor with 1 m cable

• 1 × LoRaWAN Stubby Antenna

• 1 × Transceiver Cover

• 1 × Extension Cable (1 m)

• 1 × Quick Guide

• 1 × Warranty Card

Product Downloads

📥 CT101/103 Datasheet (EN)
📥 User Guide (EN)

Product Video