CT PT Analyzer

CT PT Analyzer is a professional device for transformer testing in the power industry. Its working principle is based on a constant voltage and constant current variable frequency power supply module. CT PT Analyzer controls the power output through a DSP data acquisition system to complete various tests on current and voltage transformers (CT/PT). CT PT Analyzer can accurately measure key parameters of the transformer, such as excitation characteristics, ratio, polarity, secondary winding resistance, etc., and automatically provide a variety of CT and PT parameters.

Function Table

Technical Parameter Table

• Support CT and PT detection
• Comply with the requirements of GB 20840.3-2013, GB 20840.2-2014 and other regulations
• All testing projects can be completed by one machine without external auxiliary equipment
• Having your own mini fast printer, you can directly print test results on site
• Adopting intelligent controller, easy to operate
• Large screen LCD display, graphical display interface
• CT/PT (excitation) inflection point value is automatically given according to the program
• Automatically provide error curves of 5% and 10%
• Can save 3000 sets of test data, will not be lost after power failure
• Supports saving data on a USB flash drive, which can be read through a standard PC and generate WORD reports
• Compact structure, light weight ≤ 22kg, very suitable for on-site testing

1. Dual Functionality (CT & PT in One Device)

A single tester can perform comprehensive diagnostics on both current transformers (CT) and voltage transformers (PT), eliminating the need for two separate instruments and saving significant equipment costs.

2. High-Precision Measurements

It delivers laboratory-grade accuracy for critical parameters such as ratio error (typically ±0.05%), phase displacement, and excitation characteristics, ensuring that metering and protection systems operate correctly.

3. Automated & Intelligent Operation

Modern testers feature fully automatic, "one-key" testing. After simple wiring, the device automatically completes the test sequence, calculates knee point voltage, error curves, and other parameters, and judges if the transformer is qualified-greatly reducing the need for highly specialized technical staff.

4. Comprehensive Safety Protection

By using low-voltage (e.g., 120V) variable frequency sources instead of traditional high-current injection methods, the tester significantly reduces high-voltage risks to operators and equipment. It also includes safety features like automatic demagnetization.

5. Extreme Portability for Field Use

Weighing as little as 4-10 kg (A4 paper size), these analyzers are designed for on-site testing in substations. Their lightweight, rugged construction makes them easy to transport to remote locations, unlike traditional bulky test sets.

6. Advanced Data Management

Results can be stored internally (thousands of records), exported via USB to create Word/PDF/Excel reports, and in some models, transmitted wirelessly (Wi-Fi/Bluetooth) for cloud-based analysis and asset management.

7. Wide Testing Capabilities (Including Transient & GIS)

They support steady-state tests (ratio, polarity, resistance) and complex transient tests (time constant Ts, remanence factor Kr). They are also capable of testing specialized types like TP class CTs, GIS, and bushing transformers without external accessories.

8. Cost-Effective & Efficient

Automation reduces testing time by up to 70% compared to manual methods. The all-in-one design lowers the total cost of ownership by combining multiple functions (resistance, burden, excitation) into a single device, minimizing maintenance downtime.

9. Compliance with International Standards

These testers are designed to meet global standards such as IEC 60044, IEC 61869, IEEE C57.13, and GB/T, ensuring your test results are recognized and compliant worldwide.

10. Intelligent Diagnostic Features

Advanced models offer "nameplate guessing" for unknown transformers and use AI algorithms to analyze data trends and predict potential transformer health issues, enabling proactive maintenance strategies.

Protective Relay Calibration in Substations
Verifies the ratio, polarity, and phase displacement of CTs and PTs to ensure protective relays (e.g., overcurrent, differential) operate correctly during faults, preventing nuisance trips or failure to trip.

Revenue Metering Accuracy Verification
Tests CTs and PTs used in utility billing meters to confirm their accuracy class (e.g., 0.2S, 0.5), ensuring that commercial and industrial customers are billed correctly and revenue loss is avoided.

Transformer Differential Protection Schemes
Validates the CTs on both primary and secondary sides of power transformers, checking that their ratios and phase angles match the differential relay settings, thus preventing false differential trips during normal operation.

Generator Step-Up Transformer (GSU) Testing
Tests the high-ratio CTs and PTs at generator outputs (often 11kV to 220kV or higher) to verify accurate power measurement and protection for the generator against stator faults or overcurrent.

GIS (Gas-Insulated Switchgear) CT/PT Testing
Used where access to CT/PT terminals is limited. The tester can perform all necessary tests from the secondary side using low-voltage variable frequency methods, avoiding the need to open pressurized gas compartments.

Commissioning of New Substations & Switchgear
Performed during the initial installation of CTs and PTs to document baseline excitation curves, ratio errors, and burden values before the equipment is energized for the first time.

Periodic Maintenance in Utility & Industrial Plants
Conducted annually or bi-annually to track the degradation of CT/PT magnetic cores and insulation, helping utilities and factories schedule replacements before a failure causes unplanned downtime.

On-Site Troubleshooting of Metering or Protection Malfunctions
When a meter reads incorrectly or a relay operates without a fault, the tester is used to quickly isolate whether the issue is the CT/PT itself, the wiring, or the connected instrument.

Testing TP Class CTs for Transmission Lines
Specifically verifies the transient performance parameters (knee point voltage, exciting current, time constant Ts, remanence factor Kr) of TP class CTs used in high-speed protection schemes for extra-high voltage (EHV) transmission lines.

Quality Control in CT/PT Manufacturing & Repair Shops
Used by manufacturers to perform 100% testing of all units before shipment, and by repair shops to verify that reconditioned or rewound CTs/PTs meet their original nameplate specifications.

The CT PT Analyzer operates primarily on the low-frequency or variable-frequency method, which applies a reduced voltage (e.g., 20V at 0.5Hz) to the secondary winding of the current or voltage transformer to saturate the core at the same magnetic flux level as a much higher voltage at 50/60Hz, then mathematically converts the results back to the rated frequency. For ratio and polarity tests, it injects a low AC voltage (typically 0–120V) into the secondary winding and measures the induced voltage on the primary side to calculate the turns ratio accurately. The excitation (magnetization) curve is obtained by varying the voltage applied to the secondary winding while monitoring the resulting current, from which the knee point voltage and other core parameters are derived. Some advanced models use a DC method that rapidly saturates the core to complete the excitation test up to three times faster. Additionally, the tester measures winding resistance via the four-wire Kelvin method and secondary burden in VA, with all functions integrated into a single microprocessor-controlled instrument that automates the entire test sequence, calculates ratio error, phase displacement, error curves, and transient parameters (Ts, Kr, Ktd), and delivers a pass/fail judgment without requiring external high-voltage or high-current sources. 

We deliver speed, quality, and expertise. Request a quotation and you will receive it within one hour; need a solution, and we will provide it within 24 hours. A product demo is always available to prove our capabilities before you commit. Once you place an order, we strictly follow the contract, keep you updated on production progress, and guarantee on-time delivery. With over 100 countries served-including Malaysia, Indonesia, Saudi Arabia, the UAE, the USA, Australia, and Brazil-our export experience is deep and proven. Our modern production facilities and clean, organized office environment reflect our commitment to quality at every level. After your purchase, we respond to inquiries within six hours, offer a full 12-month warranty, provide overseas training support, and conduct regular return visits. Extended warranty and rental services are also available. We welcome factory acceptance tests, and our professional R&D and QC teams ensure every product meets your specifications. Customization is always an option, as are authorized calibration services. All of this comes with competitive pricing and a 12-month warranty-because your success is our business.

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