Transformer Performance Tester

  • JYC dielectric loss Tan Delta tester
JYC dielectric loss Tan Delta tester

JYC dielectric loss Tan Delta tester

  • Dissipation Factor Testing
  • CVT test function
  • Strong anti- interference
  • Fast test speed
  • Product description: JYC has anti interference fuction by frequency conversion during direlectric tan delta testing, and it is not necessary to change wire as CVT testing, and same time JYC can test the turn radio of CVT

The condition of the insulation is essential for secure and reliable operation of your transformer. Measuring capacitance and dissipation/power factor helps you to determine insulation condition in bushings or between windings.

Changes in capacitance can, for example, indicate mechanical displacements of windings or partial breakdown in bushings. Aging and degradation of the insulation, coupled with the ingress of water, increase the amount of energy that is converted to heat in the insulation. The rate of these losses is measured as dissipation factor.

Principle of Tan Delta Test

A pure insulator when is connected across line and earth, it behaves as a capacitor. In an ideal insulator, as the insulating material which acts as dielectric too, is 100 % pure, the electric current passing through the insulator, only have capacitive component. There is no resistive component of the current, flowing from line to earth through insulator as in ideal insulating material, there is zero percent impurity.
In pure capacitor, the capacitive electric current leads the applied voltage by 90°.

In practice, the insulator cannot be made 100% pure. Also due to the aging of insulators, the impurities like dirt and moisture enter into it. These impurities provide the conductive path to the current. Consequently, an electric leakage current flowing from line to earth through the insulator has a resistive component.

Hence, it is needless to say that, for good insulator, this resistive component of electric leakage current is quite low. In another way, the healthiness of an electrical insulator can be determined by the ratio of the resistive component to the capacitive component. For good insulator, this ratio would be quite low. This ratio is commonly known as tanδ or tan delta. Sometimes it is also referred to as dissipation factor.

JYC has anti interference fuction by frequency conversion during insulation loss testing,  and it is not necessary to change wire as CVT testing, and same time JYC can test the turn radio of CVT.

● JYC transformer dielectric tan delta tester adopts frequency conversion technology to eliminate field frequency 50Hz, even in frequency interference strong electromagnetic interference environment also can be measured reliably

● Applies big screen dot matrix LCD, testing process through the English menu is intuitive and easy to operating.

● JYC transformer dielectric tan delta tester is a integration tester with standard capacitance and high voltage power supply to bring convenience to on spot test and reduce field wiring

● JYC has CVT test function to realize CVT test by self-excited without external accessories, also JYC can measure CVT voltage ratio function during insulation loss testing.

● Can realize anti-ground wiring measurement, small capacitance ground testing accurately.

● JYC has over-current protection function to ensure the sample will not damaged in short circuit or electric shock

● JYC transformer dielectric tan delta tester is suitable for all power supply unit with a number of CVT units and requiring a high degree of automation.



JYC Tan delta tester


Cx: ±(Reading×1%+2pF)

tgδ: ±(Reading×1%+0.00040)

Anti-interference index

With frequency conversion anti-interference, the above accuracy can be achieved under 200% interference.

Capacitance range

Internal application of high voltage: 3pF60,000 pF/10kV, 60pF1µF/0.5kV

External application of high voltage: 3pF1.5µF/10kV, 60pF30µF/0.5kV

Resolution: Max. 0.001pF, 4 valid digits

Range of tgδ

No limit, resolution:0.001%. Identify capacitive, inductive and resistivetested products automatically.

Test current range


Internal application high voltage

Setting voltage range: 0.510kV

Max. output current: 200mA

Up-down voltage mode: Continuous smoothing

Voltage precision: ±(1.5%×reading+10V)

Voltage resolution: 1V

Testing frequency: 45,50,55,60,65Hz, single frequency

45/55Hz, 55/65Hz, 47.5/52.5Hz, automatic dual frequency

Frequency precision: ±0.01Hz

External application high voltage

Maximum test current at positive connection: 5A, Power frequency or conversion frequency: 4070Hz

Maximum test current at negative connection: 10kV/5A, Power frequency or conversion frequency: 4070Hz

CVT self excitation low voltage output

Output voltage: 350V, output current: 330A

Test time

About 15s, relating to the testing mode

Input power

180V270V AC, 50Hz/60Hz±1%, Grid power or generator

Environmental temperature


Relative humidity

≤80% RH, no dew

Volume / Weight

L430mm*W320mm*H330mm / 29 kgs