The HW‑group 30A AC Current probe 1W‑UNI 2 is a modern, flexible solution for single-phase AC current measurement up to 30 amperes. Its standout feature is the indirect measurement through a split-core current clamp transformer, meaning the conductor does not need to be cut. This makes the sensor ideal for retrofitting in existing installations without downtime or complex setup.

As part of the HW‑group 1‑Wire‑UNI sensor family, the 30A AC Current probe can be seamlessly integrated into monitoring systems such as Poseidon2, Ares, STE2, and SiteMon. Via RJ11 connection, measurement data is transmitted in real time to the monitoring system and then made available via LAN, GSM, SNMP, or Modbus/TCP for centralized analysis, trend monitoring, and alarm handling.

With galvanic isolation, the sensor ensures both reliability and operational safety. The measurement principle eliminates direct electrical contact with the high-voltage circuit, providing optimal protection for technicians and connected monitoring hardware.

Measurement Principle – Safe and Non-Contact

The integrated current clamp encloses a conductor and measures the alternating current flowing through it using the magnetic field. As a split-core design, it can be easily opened and closed during installation. This allows the sensor to be placed anywhere on an insulated power cable (phase L or neutral N) without interrupting operation.

This is particularly advantageous in data centers, telecommunications base stations (BTS), or industrial facilities where interruptions are costly or technically infeasible. The recorded values—from standby to full load—enable operators to precisely monitor device utilization and energy flow.

Technical Performance and Accuracy

The 30A AC Current probe 1W‑UNI 2 measures current in a range of 0 to 30 amperes with an accuracy of ±2 % of full scale. The resolution of 0.1 A ensures that even minor load changes are reliably detected. The sensor is suitable for supply voltages up to 400 V AC (compatible with 110V/60Hz and 230V/50Hz systems).

Measurement data is transmitted in the 1‑Wire‑UNI format, guaranteeing consistent integration with HW‑group monitoring systems. Up to two current sensors can be connected per RJ11 port, and with the Poseidon2 4002, up to eight, providing a scalable energy measurement solution.

Galvanic Isolation – Safety and Signal Integrity

Galvanic separation between the measurement circuit and the communication line prevents voltage surges or electrical noise from entering the monitoring network. This protects both the connected device and the user. At the same time, it enhances measurement precision by reducing electrical interference.

Simple Installation for Quick Results

Installation is straightforward: open the split-core clamp, place it around the selected conductor, close it again, and route the insulated connection cable to the 1‑Wire‑UNI interface unit. The device connects to the monitoring system via RJ11 ports. As the sensor is bus-powered, no external power supply is required.

The compact design and daisy-chain capability allow multiple sensors to be installed efficiently in racks or control cabinets. Even in confined environments such as densely packed server rooms, the 30A AC Current probe can be easily deployed.

Application Areas

• Server rooms & data centers: Load monitoring of single racks or larger server clusters.
• Telecommunication BTS stations: Current measurement in supply lines for early detection of overload conditions.
• Industrial manufacturing: Monitoring power consumption of individual machines or production lines.
• Remote monitoring: Automatic notifications when predefined load thresholds are exceeded or undershot.
• Energy optimization: Data-driven planning to reduce operational costs.

Technical Specifications

• Measurement range: 0 – 30 A AC
• Accuracy: ± 2 %
• Resolution: 0.1 A
• Rated voltage in measurement circuit: max. 400 V AC (110V/60Hz, 230V/50Hz)
• Interface: 1‑Wire UNI (2 × RJ11)
• Power supply: bus-powered
• Connection: split-core clamp (phase or neutral, insulated)
• Operating temperature: –30 °C to +85 °C
• Humidity: 0 % to 100 % RH
• Protection class: IP20
• Weight: approx. 180 g

Integration and Data Analysis

Combined with HW‑group devices such as Poseidon2 or Ares, the current sensor can be seamlessly integrated into existing monitoring solutions. These central units then transmit measurement data via LAN or GSM to control centers, SCADA systems, or cloud portals such as SensDesk. Users can analyze load curves, compare historical data, and configure real-time alarms as needed.

Using the free HWg‑PDMS software, collected data can be exported to Excel, enabling detailed reports for energy management, audits, and internal documentation.

The 30A AC Current probe 1W‑UNI 2 combines simple installation, high measurement precision, and maximum safety. Thanks to split-core technology, no intervention in the electrical installation is required, making it especially suitable for live IT and industrial environments. The ability to integrate the sensor into any HW‑group monitoring infrastructure provides a flexible and scalable solution for professional current measurement and remote monitoring.

For operators of data centers, telecommunications systems, or industrial facilities, the 30A AC Current probe 1W‑UNI 2 is an essential tool to ensure optimal energy availability and transparency.