HF-LT-309 Wireless Insulator Insulation Resistance Tester

There are many methods and tools for detecting insulators at present. However, most of them only provide qualitative detection, which cannot accurately and quickly test the insulation status of each single insulator and fail to realize preventive inspection. The insulation resistance value of insulators on high-voltage transmission lines directly affects the stable and safe operation of power grids. Once insulators become zero-value or contaminated, cleaning or replacement must be carried out; otherwise, flashover tripping faults will occur.

In view of the above requirements raised by numerous users, our company has successfully developed this new high-performance quantitative testing and analysis instrument — HF-LT-309 Wireless Insulator Insulation Resistance Tester after extensive field tests. The instrument can effectively detect hidden internal faults of insulators, improve the reliability of power grid operation and boost work efficiency for field line crews. Featuring simple and fast operation, it mainly performs accurate quantitative measurement of resistance of each insulator under power-off conditions. It can distinguish insulators with leakage current yet approaching critical damage, record and display measured data in real time, and automatically trigger voice alarms for low-value insulators.

HF-LT-309 Wireless Insulator Insulation Resistance Tester adopts wireless transmission. The communication distance between the probe and handheld terminal reaches over 100 meters, enabling safe, fast and accurate measurement. Besides, the instrument boasts strong anti-interference capability, complies with EMC standards, and adapts to working sites with various electromagnetic field interferences.

Tests shall be carried out in dry weather.
Operate this product in accordance with specifications to guarantee safe instrument operation.
Abide by the safety regulations for preventive tests of power industry safety tools.
Attach great importance to training and assessment of staff working on or near high-voltage transmission lines.
Install an insulated operating rod for overhead live-line operations.

High voltage exists between the two probes during testing. Direct human contact is strictly prohibited.
Switch off the power supply and wait for 3 seconds before installing or adjusting probes.

Attachment: Specifications for Safe Use and Test Standards of Insulated Rods for Wireless Insulator Insulation Resistance Tester

Note: Standard for sectional routine inspection test of insulated tools: apply 75kV power frequency voltage for every 300mm within 1 minute. No breakdown, flashover or overheating is acceptable.

HF-LT-309 Wireless Insulator Insulation Resistance Tester complies with standards listed below:

◎ Applicable for operating voltage: 35~500kV, compatible with all voltage grades
◎ Measuring resistance range: 10 ~ 3000 MΩ
◎ Measuring error: ≤±10%
◎ Sampling rate: 10 times per second
◎ Date & time setting: adjustable for data review and historical record query
◎ Backlight timer: constant on, constant off or freely set within 0~999 minutes
◎ Auto power-off timer: freely set within 0~999 minutes or disable
◎ Max. transmission distance between handheld terminal and probe: ≤100m
◎ Multi-mode design for enhanced adaptability, safety and convenience
◎ Universal joint design: adjust measuring direction flexibly according to suspension position of insulator strings
◎ Double-layer shielding design with strong anti-interference performance, conforming to EMC standards
◎ User-friendly human-machine interface for easy operation
◎ Removable battery cover for convenient battery replacement

Switch on the probe; the green LED lights up. Secure the universal joint at the bottom of the probe onto the telescopic insulated rod. Extend the rod to appropriate length and adjust measuring orientation. Connect probe A and probe B directly to the metal fittings at both ends of the tested insulator (power-off status). Press the [OK] key on the handheld terminal to initiate measurement. One beep indicates completion of testing on one insulator. The LCD displays “Testing” and “Test Succeeded”, and you can read and save the measured resistance value.

If the LCD displays “>3000MΩ”, the insulator resistance exceeds 3000MΩ, indicating sound insulation performance.

For voltage levels ≤220kV: if insulator resistance is lower than 300MΩ, the handheld terminal will trigger continuous triple voice alarm to notify low-value insulators.
For voltage levels above 220kV: if insulator resistance is lower than 500MΩ, the handheld terminal will trigger continuous triple voice alarm to notify low-value insulators.

The handheld terminal automatically displays remaining battery capacity after power-on.
Replace batteries when power is low before further operation.

Handheld terminal battery compartment: 2 pcs of 1.5V AA alkaline batteries
Probe: built-in high-capacity lithium battery; charging port located on the left side
Use original matching power adapter. LED flashes during charging and turns green once fully charged.

FAQ | Wireless Insulator Insulation Resistance Tester

Q1: What voltage levels of transmission lines is this tester applicable to?

Q2: What is the measuring resistance range?

Q3: What is the wireless transmission distance between probe and handheld terminal?

Q4: When will the instrument trigger voice alarm for low-value insulators?

Q5: Can it work under strong electromagnetic interference on site?

Q6: What are the power supply modes for the probe and handheld terminal?

Q7: Does the tester support historical data storage?

Q8: Can I perform testing on rainy or humid days?

Q9: Is it necessary to power off the line before insulator testing?

Q10: What is the continuous working time after full charging?