Xutongyongfu XT-200A Portable AC/DC High-Voltage Dielectric Withstand Tester for HV Motors

Overview

The Xutongyongfu XT-200A Portable AC/DC High-Voltage Dielectric Withstand Tester is an integrated, field-deployable solution engineered for routine dielectric integrity verification of high-voltage induction motors and synchronous machines. Unlike conventional test setups requiring separate AC test transformers and DC high-voltage generators—each with associated oil-filled tanks, heavy grounding systems, and multi-cable interconnections—the XT-200A consolidates both AC power-frequency (50 Hz) and DC polarization testing into a single, self-contained unit. Its operation is based on solid-state voltage generation and regulated step-up transformation, delivering stable, low-ripple DC output and sinusoidal AC output synchronized to grid frequency. The instrument is specifically designed for commissioning (acceptance) testing per GB 50150–2006 and periodic preventive maintenance per DL/T 596–2005, supporting verification of insulation resistance, leakage current stability, and breakdown threshold under controlled ramp-and-hold protocols.

Key Features

• Integrated AC/DC high-voltage generation in one chassis—eliminates need for external HV transformers or DC stacks
• Lightweight design (22 kg) with compact footprint (400 × 300 × 300 mm), enabling single-operator transport and setup in confined substations, turbine halls, or motor repair workshops
• Dual-range calibrated output: AC up to 15 kV RMS / DC up to 25 kV, with ±1.5% full-scale accuracy traceable to national metrological standards
• Active current compensation architecture: supports load currents up to 550 mA via optional multi-tap air-core compensating reactor—each tap labeled with nominal reactive current compensation value (e.g., 100 mA, 200 mA, 300 mA)
• Zero-position interlock and manual ramp control ensure operator safety and procedural compliance during voltage application
• Analog pointer meter display provides real-time, EMI-resistant readout of output voltage and current—no dependency on digital displays vulnerable to transient-induced glitches
• Embedded protection suite: overcurrent cutoff (6.7 A primary-side trip), time-based automatic de-energization (0–999 s adjustable), and thermal foldback circuitry
• Core construction utilizes grain-oriented silicon steel laminations, vacuum-impregnated epoxy insulation, and non-hygroscopic magnetic alloys—ensuring stable performance across humidity extremes (≤90% RH at +25 °C) and ambient temperatures from −15 °C to +50 °C

Sample Compatibility & Compliance

The XT-200A is validated for dielectric testing of stator windings in medium-voltage rotating machines rated 6 kV and 10 kV class, including squirrel-cage and wound-rotor induction motors, as well as salient-pole and cylindrical-rotor synchronous motors. It accommodates winding capacitances ranging from 50 nF to 2.5 µF through its adaptive reactor compensation system. All electrical safety design elements conform to IEC 61010-1:2010 (Measurement Category CAT II 300 V, Pollution Degree 2). Test procedures executed with this instrument satisfy mandatory requirements of GB 50150–2006 (Acceptance Tests for Electrical Installation Projects), DL/T 596–2005 (Preventive Testing Code for Power Equipment), and DL/T 848.2–2004 (General Technical Conditions for Power-Frequency HV Test Systems). While not certified to UL 61010 or EN 61010 for export markets, its architecture permits third-party assessment for CE marking under Low Voltage Directive (2014/35/EU) when installed with appropriate external earthing and interlock integration.

Software & Data Management

The XT-200A operates as a standalone analog instrument without embedded microprocessor control or digital data logging. Voltage ramp rate, hold duration, and termination criteria are set manually using front-panel controls; all operational parameters—including applied voltage, measured leakage current, and elapsed time—are monitored via analog meters. This architecture intentionally avoids firmware dependencies, ensuring long-term operational continuity without software obsolescence, cybersecurity exposure, or validation overhead. For laboratories requiring documented test records, users may integrate external calibrated data loggers (e.g., HIOKI MR6000 or Fluke 2638A) connected to the instrument’s analog output terminals (0–10 V proportional to kV and mA). Such configurations support audit-ready traceability aligned with GLP and internal QA protocols—though native 21 CFR Part 11 compliance is not implemented, as no electronic records are generated internally.

Applications

• Factory acceptance testing (FAT) of new HV motors prior to site delivery
• Site commissioning tests following installation and connection to switchgear
• Biannual or triennial preventive maintenance per utility asset management schedules
• Troubleshooting insulation degradation after fault events (e.g., lightning strikes, switching surges)
• Verification of rewound stator winding integrity post-repair
• Baseline dielectric characterization during motor life-cycle assessment programs

FAQ

Does the XT-200A support automated test sequences or programmable voltage ramps?
No. It is a manually operated analog instrument. Voltage is increased incrementally via hand-adjusted variac; timing and termination are user-determined.

Can it be used for cable or transformer testing?
It is optimized for motor stator windings. While technically capable of applying rated voltage to other capacitive loads, its current capacity and compensation design are calibrated specifically for motor winding impedance profiles—not transmission cables or power transformer bushings.

Is calibration documentation provided with shipment?
Yes. Each unit ships with a factory calibration certificate indicating as-tested voltage and current accuracy against reference standards, valid for 12 months under normal use conditions.

What safety certifications does the unit carry?
It complies with GB/T 16927.1–2011 (High-voltage test techniques) and incorporates dual redundant grounding points, insulated HV output terminals, and visible zero-voltage interlock indicators—meeting domestic Chinese safety practice requirements for Class I portable HV equipment.