A ceramic insulator sensor captures three-phase partial discharge and overvoltage signals at the transformer high-voltage side of low-voltage distribution lines. This article explains the HMJ1010-WTX and its role in distribution network monitoring.
Ceramic Insulator Sensor for Distribution Lines: PD and Overvoltage on Three Phases Read More »
Capacitor banks fail when a unit short-circuits or ages, and the failure is often electrical before it is visible. An online monitoring terminal measures voltage and current in real time to catch abnormal conditions early. This article explains the HMJ1011-IA1.
High Voltage Capacitor Bank Monitoring: Real-Time Voltage and Current Supervision Read More »
A lightning arrester leakage current monitor tracks the resistive component of MOA leakage current, detects varistor ageing and moisture, and counts lightning strikes. This article explains the HMJ1011-WBJ and how to read its data.
Lightning Arrester Leakage Current Monitor: Online Tracking of MOA Resistive Current Read More »
A high-voltage live display PD terminal shows whether a busbar is energised and monitors partial discharge on all three phases, communicating over RS485 Modbus. This article explains the HMJ1010-WCK and its role in switchgear and RMU monitoring.
High-Voltage Live Display PD Terminal: Combining Busbar Indication and PD Monitoring Read More »
A spatial UHF sensor monitors the ultra-high-frequency PD signal within a switchgear room or RMU bay, detecting discharge inside panels that have no internal port. This article explains the 300-1500 MHz spatial approach and the HMJ1010-WGK.
Spatial UHF Partial Discharge Sensor for HV Switchgear Rooms and Ring Main Units Read More »
A two-in-one partial discharge sensor combines transient earth voltage and ultrasonic detection in a single unit for switchgear and ring main units. This article explains why the combination covers more defects and how the HMJ1010-AT is installed.
Two-in-One TEV and Ultrasonic PD Sensor for Switchgear and RMU Monitoring Read More »
Oscillating wave testing (OWTS, or damped AC – DAC) stresses a cable with a damped alternating wave and measures partial discharge while the cable stays in serviceable condition. This article explains the method and the HMJ9031 cable oscillating wave tester.
Non-dispersive infrared (NDIR) SF6 detectors measure gas concentration with dual-beam dual-wavelength optics and no consumable sensors. This article explains the technology and the HMJ-9051-S infrared quantitative leak detector for GIS substations.
NDIR SF6 Leak Detection: Dual-Beam Infrared Measurement for Substation Surveys Read More »
Inter-turn short circuits in generator rotors are common and dangerous if missed. Recurrent Surge Oscilloscope (RSO) testing detects them during overhauls without disassembling the rotor. This article explains the method and the HMJ7001 RSO detector.
SF6 leaks are expensive and environmentally significant, and they must be found and quantified. The negative ion capture principle gives a sensitive, stable and fast way to locate leaks on circuit breakers and GIS. This article explains how the HMJ-9051-SJ detector works.