200A Desktop Loop Resistance Tester

200A Desktop Loop Resistance Tester

MOEORW-WKH200C is AC mains-powered bench-type loop resistance tester designed complying with SD301-88 and DL/T845.4-2004 industry specifications, specially developed for high-current DC resistance measurement of HV switchgear contact loops. It features stable continuous output up to rated 200A DC to break through surface oxidation layer of switch contact points and acquire authentic contact resistance value. Integrated embedded thermal printer, USB data export and optional Bluetooth communication function support full digital data management and standardized test report output, widely deployed in power generation plants, substations and heavy industrial electrical maintenance departments. The wide-temperature LCD display eliminates display failure issue under direct strong sunlight exposure during field outdoor testing.

1. Hardware Configuration & Structural Design

• Integrated desktop integral cabinet structure with built-in regulated high-power constant current source powered directly by AC220V mains without internal lithium battery; front panel pre-installed embedded thermal printer, independent C1/C2 current terminals and P1/P2 voltage input terminals with locking rotary interface structure for secure cable fixation.· Wide operating temperature customized Chinese LCD module to adapt harsh outdoor high-temperature & strong sunlight working environment without screen blackout or failure.· Independent reset button and main power cut-off switch for rapid equipment reset after abnormal test termination.

2. Core Performance Characteristics

• Stable continuous constant current output at optional 100A or 200A; large DC excitation effectively ablates contact surface oxide film to eliminate false high-resistance reading caused by oxidation layer blocking conductive path.· Four-wire Kelvin measuring architecture strictly isolates current loop and voltage sampling loop to exclude inherent resistance of connecting test leads from final measured value, guaranteeing ultra-high test accuracy down to 0.01μΩ resolution.###3. Practical Field Value· User-friendly menu-driven operation without manual potentiometer adjustment; parameter setup (current & test duration) fully via up/down navigation keys on LCD menu.· Diversified data management: onboard print via embedded printer, USB disk data backup, optional Bluetooth data upload to PC for standardized A4 test report generation, improving laboratory & field file archiving efficiency.· Preheating function available for high-precision measurement requirement: idle short-circuit preheat 1min with 60s preset test time before formal specimen testing to stabilize internal constant-current source output precision.

1. Handover acceptance test and regular preventive maintenance test for HV circuit breakers, isolating switches in utility power station and distribution substation.

2. Contact loop resistance inspection of high-current busbar connecting fittings for heavy-load industrial enterprises, metallurgy and petrochemical power consumption equipment.

3. R&D sampling test for switchgear manufacturing factory component incoming inspection and finished product quality verification.

• SD301-88: Specification for handover & preventive test of 500kV AC power equipment· DL/T845.4-2004: General technical specification for resistance measuring instrument Part4: Loop Resistance Tester

1. Pre-operation Cable Management: Fully unfold bundled test leads before startup; prohibit coiling leads tightly to avoid eddy current effect interfering measurement accuracy.

2. Seasonal Damp Prevention: For humid environment storage, monthly power-on operation for continuous 2h to drive internal chassis moisture and protect circuit components from damp corrosion.

3. Sun Protection: Avoid long-time direct solar irradiation targeting LCD screen during outdoor field test to extend display service life.

4. Long-term Storage: Keep equipment in dry warehouse within -20℃~60℃, RH＜85% with corrosion-free ambient gas; adopt carton or wooden case with foam padding during cross-region transportation for anti-shock protection.

1. Large measurement deviation: Check test lead layout; confirm voltage fine clips are clamped inside current big clips; polish rust/paint coating at DUT clamping position to eliminate contact barrier resistance; fully spread test cables without overlapping winding.

2. No printer output after measurement: Check printer paper installation status; verify printer power connection and paper roll remaining quantity before re-trigger print instruction.

3. Device fails to power on after mains connection: Inspect built-in 5A fuse inside AC power socket; replace matched specification fuse once blown caused by short-circuit overload.