AC Hipot Test Set

Looking for reliable AC dielectric withstand test equipment tailored to your specific voltage levels and application needs? Explore Weshine’s full lineup of high-precision electrical testing solutions.

Contact Weshine’s engineering specialists today for technical support, customized kVA capacity designs, and a competitive quotation for your project.

AC Hipot Tester & AC Withstand Voltage Test Equipment

An AC Hipot Tester (AC Dielectric Withstand Voltage Tester) is an essential high voltage instrument designed to test electrical insulation integrity under alternating current conditions. Because AC testing subjects insulation to reversing voltage polarities—closely mirroring real-world electrical stress—it is widely recognized by international standards (such as IEC and IEEE) as the most effective method for detecting insulation defects, insulation degradation, and manufacturing flaws in high-voltage apparatus.

As a leading provider of professional Electrical Testing Solutions, Weshine offers a comprehensive series of AC hipot test sets, including dry-type, oil-immersed, and SF6 gas-insulated testing transformers, as well as digital control systems. Engineered for high accuracy, continuous stability, and maximum operator safety, our AC hipot testers deliver dependable withstand voltage testing for power transformers, switchgear, bushings, insulators, and heavy electrical machinery.

Whether you require portable AC hipot units for field acceptance testing or high-capacity systems for factory routine inspection, Weshine provides versatile Power Testing Equipment engineered to handle demanding industrial environments.

Featured AC Hipot Testing Systems

Explore some of our most popular high-voltage AC withstand test sets engineered for different voltage classes and heavy-duty industrial applications:

• 100kV AC Hipot Test System

  Ideal for medium-voltage testing applications. Designed for routine and field insulation withstand voltage testing of distribution transformers, switchgear, vacuum circuit breakers, and medium-voltage electrical components. Offers compact portability combined with precise leakage current monitoring.

• 250kV AC Hipot Test System

  Versatile solution for high-voltage substations and electrical manufacturers. Built to handle demanding dielectric tests on high-voltage switchgear (GIS/AIS), power transformers, substation bushings, and insulation components requiring higher voltage thresholds with superior wave stability.

• 500kV AC Hipot Test System

  Ultra-high voltage (UHV) testing capability. Engineered for heavy-duty factory acceptance testing (FAT), research laboratories, and extra-high-voltage power grid maintenance. Delivers continuous, high-capacity AC test voltage for ultra-high voltage apparatus and complex capacitive loads.

Key Features of Weshine AC Hipot Testers

Weshine AC withstand voltage test sets combine robust high-voltage transformer engineering with intelligent digital control units to ensure accurate insulation diagnosis and operational reliability.

• Realistic AC Insulation Stressing: Tests insulation under actual operating frequency (50Hz / 60Hz), providing a true reflection of dielectric performance without DC polarization effects.

• Flexible Insulation Mediums: Choose from Dry-Type (compact and maintenance-free), Oil-Immersed (cost-effective with high heat dissipation), or SF6 Gas-Insulated (lightweight and pollution-free) testing transformers based on field or lab conditions.

• Precise Voltage & Leakage Current Monitoring: Integrated digital microcontrollers continuously monitor output voltage, breakdown current, and test timing with low distortion waveform output.

• Multi-Layer Safety Protections: Features zero-voltage start interlock, fast-acting over-voltage and over-current protection, emergency stop button, and dedicated grounding protection to ensure complete operator safety.

• Customizable Output & Capacity: Available in wide voltage ranges (from 5kV up to 500kV+) and customizable capacity ratings (kVA) to suit specific capacitive loads and testing standards.

Applications of AC Withstand Voltage Testers

AC hipot testing is mandatory across the manufacturing, installation, and maintenance cycles of power infrastructure. Weshine AC withstand voltage test sets are widely deployed in:

1. Power Transformer Testing

Used to conduct main insulation and inter-turn insulation dielectric strength tests on step-up/step-down transformers, distribution transformers, and instrument transformers (CT/PT).

2. Switchgear & Substation Equipment

Verifies the dielectric clearance and insulation soundness of Gas-Insulated Switchgear (GIS), Air-Insulated Switchgear (AIS), vacuum circuit breakers, and high-voltage bushings.

3. Electric Motors & Generators

Evaluates the stator and rotor winding insulation performance under alternating stress for large industrial motors and hydro/thermal power generators.

4. Insulators, Bushings & Power Components

Used by high-voltage component manufacturers for factory quality control, routine withstand tests, and type testing of ceramic/composite insulators, cable accessories, and surge arresters.

AC Hipot Tester vs. DC Hipot Tester: Key Differences

Understanding when to choose an AC hipot test set versus a DC unit is critical for accurate insulation evaluation:

Feature	AC Hipot Tester	DC Hipot Tester
Stress Type	Reversing alternating field (simulates grid conditions)	Unidirectional direct current field
Capacitance Effect	Requires higher power to supply capacitive charging current	Negligible charging current after initial charge
Insulation Evaluation	Stresses insulation evenly across dielectric layers	Stresses insulation based on resistive distribution
Best Suited For	Transformers, switchgear, motors, insulators	High-capacitance cables, DC power equipment, generators

How to Choose the Right AC Hipot Tester

When selecting an AC hipot test system from our range of Power Testing Equipment, consider the following technical parameters:

1. Required Output Voltage (kV): Determine the maximum withstand test voltage required by relevant industry standards (e.g., IEC 60060, IEEE C57).

2. Required Power Capacity (kVA): Calculate the capacitive load current (I = 2π × f × C × U) of your test specimen to ensure the testing transformer has adequate kVA capacity.

3. Operating Environment: Select Dry-Type or SF6 models for lightweight field portability, or Oil-Immersed models for rugged industrial environments.

4. Control System Preference: Choose manual analog control units for cost efficiency or automated digital consoles for automatic voltage ramp-up, timing, and report printing.

Frequently Asked Questions About AC Hipot Testers

Q1: What is an AC hipot test used for?

An AC hipot test applies high AC voltage between an electrical equipment’s live conductors and its grounded chassis. It stresses the electrical insulation to ensure it can safely handle transient operational overvoltages without insulation breakdown or current flashover.

Q2: Why is AC hipot testing preferred over DC testing for transformers and switchgear?

AC hipot testing stresses the insulation in both positive and negative directions, closely replicating real AC grid operating conditions. Unlike DC testing, it does not leave residual static charges in solid insulation, making it a safer and more accurate test for AC power equipment.

Q3: How do I calculate the required kVA capacity for an AC hipot tester?

Capacity (kVA) is determined by multiplying the maximum test voltage (kV) by the capacitive current (A) drawn by the test object. Long cables or large capacitive specimens require higher kVA capacity, or can be tested using resonant test systems or VLF test sets.

Q4: Are Weshine AC hipot testers safe for on-site field testing?

Yes. All Weshine AC hipot systems incorporate comprehensive safety mechanisms including zero-start interlocks, adjustable over-current protection, over-voltage trip protection, and fast grounding circuits to protect both operator and equipment.