At circuit breaker maintenance sites, loop resistance measurement results directly affect the judgment of contact conditions. O&M personnel usually need to complete tests on multiple switches within a power outage window and quickly compare historical data. The HLD-100P Intelligent Loop Resistance Tester is designed for this step, using single-chip control to automatically perform tests and reduce human intervention.
Conventional loop resistance testers require manual current adjustment, data recording, and resistance value conversion. The HLD-100P uses single-button operation. After startup, it automatically completes current output, voltage acquisition, and resistance calculation, and the test data is displayed directly on the LCD screen. For scenarios requiring continuous testing of multiple devices, this process can reduce deviations caused by repetitive operations.
The instrument uses dual-channel high-speed 16-bit Σ-Δ analog-to-digital converters to sample the test current and voltage signals separately. Two current ranges, 100A/50A, are selectable, and the open-circuit voltage meets on-site testing requirements. Under the same test conditions, the resistance values obtained from repeated tests on the same contact fluctuate little, making it convenient for O&M personnel to compare historical data.
In addition to LCD display, test results can be output through the built-in printer. After on-site testing is completed, O&M personnel can directly attach the printed data to maintenance records, reducing manual transcription. The instrument is suitable for contact resistance measurement of circuit breaker contacts, busbar connections, disconnector contacts, and other locations.
Before testing, confirm that the circuit under test is de-energized and disconnect the grounding switch connected to the system. The current leads should be as short as possible and have good contact, and the voltage clips should be clamped inside the current leads to avoid errors introduced by lead resistance. The instrument panel is equipped with a power switch and a test button, and the operation steps are simple.
