Resistance tester UHV-H100B

high-voltagecontinuityloop impedance

Overview
The UHV-H100B contact loop resistance tester combines high-frequency switching power supply technology and digital measurement circuits to provide direct measurement of circuit resistance for switchgear and control equipment. It supports recommended DC test currents of 100 A and 200 A and displays final results numerically, delivering accurate and stable measurements for field maintenance and factory testing of high-voltage switchgear.

Technical parameters

• Measuring range: 1–1999 μΩ
• Resolution: 1 μΩ
• Test current: DC 100 A fixed output (supports DC 100 A and 200 A per national standards)
• Measurement accuracy: 0.5% ± 1 digit
• Operation mode: continuity
• Display: 3.5‑digit digital display
• Power supply: AC 220 V ±10%, 50 Hz
• Operating environment: Temperature −10 ℃ to 40 ℃; humidity ≤ 80% RH
• Diemension: 390×300×150mm3
• Weight: 6kg(excluding attachments)

Precautions

• Read the instruction manual carefully before use.
• Follow the wiring method shown in the manual when connecting leads.
• Do not use the instrument to measure circuit resistance on live circuits.
• Ensure reliable grounding during use.
• Do not replace current-carrying leads or internal parts without authorization.
• When not in use, store the instrument in a ventilated, dry, cool and clean place; avoid moisture and corrosive gases.

Basic knowledge of contact resistance

• Definition: Contact resistance is the additional resistance that appears where a stationary contact meets a moving contact.
• Components: It comprises constriction (contact) resistance and surface resistance of the contact parts.
• Causes of excessive contact resistance: contact burning after interruption of large short-circuit currents; poor mechanical adjustment or unstable fixation changing stroke, pressure or contact area; oxidation after long idle periods; spring deformation reducing contact pressure; mechanical wear; corrosion or residues in oil-filled breakers.
• Factors affecting contact resistance: material properties (resistivity, hardness, chemical and mechanical properties), contact form (point/line/surface), surface condition (oxide films), contact pressure and surface roughness.

Applications

• On-site maintenance of high-voltage switchgear, factory circuit resistance testing of switchgear, and inspections by power utilities and service departments.

Maintenance and upkeep:

• The equipment should be placed indoors in a dry, dust-free, ventilated, and non corrosive gas environment. Stacking and discharging are not allowed without wooden box packaging. When storing equipment, the panel should face upwards. And place moisture-proof materials at the bottom of the equipment to prevent it from getting damp.