HES CT PT Test System

Our CT PT test system offers you a safe and reliable scheme for current and voltage transformer phase error and ratio error test.



Instrument transformer is one of the most essential means in energy measuring. Our CT PT test system offers you a safe and reliable scheme for current and voltage transformer verification. It is in accordance with international standard.


The CT PT test system is able to carry out the test including ratio error and phase error of CT and PT, impedance and admittance.


Our CT PT test system mainly consists of the following items.

HES Control Panel

HES transformer test bench is a special equipment used in the test of transformer. It is made of metal with castors, which is convenient to move. It has built-in main voltage regulator for adjustment of output current (voltage) (coarse adjustment) and auxiliary regulator (micro adjustment).

Structure will be designed according to customer’s requirement.

Main Technical Specification

  • Input power supply: AC 220V±10%, frequency 50Hz or 60Hz
  • Output power supply AC 0-250V
  • Frequency: 50Hz
  • Main voltage regulator: rated capacity 10KVA ~ 30KVA 
  • Wave distortion <5%
  • Display

Input voltage: 3 digit meter, class 1.5

Input current: 3 digit meter, class 1.5

  • Protection function

Protection when input voltage ≥280V

Protection when output current≥30V

  • Demagnetization function

It is recommended to use open circuit demagnetization during verification of CT under class 0.2; while for those CT above class 0.2 it is recommended to use closed circuit demagnetization.

HES-1C series Digital Transformer Tester

The model HES-1S/HES-1C digital transformer tester is a modern tester with advanced technology for fast, accurate measurement of instrument transformer errors.  It is designed for use in laboratories, manufacturing processes, quality control procedures and official metrology station. Because of its compact design and light weight, it is also suitable for field test.

It will sample directly the error signal, through calculation, display simultaneously percentage reading, in-phase error, quadrature error of transformer. The tester is easy in operation, direct in reading.


  1. Modern with advanced technology and automatic measurement. The measuring results can be read directly from digital displays.
  2. Digital display simultaneously percentage reading, in-phase error, quadrature error of transformer.
  3. Use with secondary current 5A, 1A or secondary voltage 100V, 100/√3V, 110V  and can be replaced to 110/√3V, 100/3V, 200V or 220V etc. upon request.
  4. Measure secondary impedance of tested transformer.
  5. Measure secondary voltage drop together with isolated PT and controlling cabinet.
  6. Automatically indicate polar.
  7. Its built-in self-test circuit can monitor the precision of instrument itself.
  8. Easy in operation, fast in measurement, compact in design, suitable for field test.
  9. HES-1C is with RS232 interface
HL Series Standard Current Transformer (with current source)

HL series standard current transformer is used as a reference transformer for current transformer measurement. Its steel core use high quality perm alloy, processed by special heat treatment and shielding protection, which features high accuracy, good error linearity. It is of compact design, nice appearance, and simple wire connection.

Technical Specification

  • Rated primary current range 5~10000A (or upon request)
  • Rated secondary current 1A , 5A or 1A and 5A
  • Rated frequency 50 Hz or 60Hz
  • Accuracy class 0.05; 0.02; 0.01

      Class 0.05s; 0.02s; 0.01s

  • Capacity 5 VA
  • Power factor cosφ=1.0
  • Current working range: 5–120% rated current value
  • Rated working voltage: 500V
  • Capacity of current source: depending on current transformer
FY49 Current Burden

The FY49 series current burden is used as an artificial load for current transformer measurement according to international standard.

Main Technical Specification

  1. Rated working current: 1A, 5A, or combined type 1A&5A
  2. Working current range: 5~120%
  3. Rated impedance: cosφ=0.8: 2.5 ~60 VA ; cosφ=1.0: 2.5 ~10 VA, (or upon request)
  4. Power factor : 0.8 & 1.0 (0.9 upon request)
  5. Limits of error:± 3%
  6. Rated frequency: 50 Hz or 60Hz
FY Series Voltage Burden

FY series voltage burden is used as an artificial load for voltage transformer measurement according to international standard.

Main Technical Specification

• Rated secondary voltage 100V, 100/√3V 110V, 110/√3V, 240V, 240/√3V or upon request (combination type for 2 range or 4 range is acceptable)

• Working voltage range: (20~120%)Un

• Power factor: 0.8

• Limits of error: ±3%

• Rated Capacity: 1.25, 2.5, 5, 10, 20, 40, 80 VA  (max. 158.75VA) or up to 308.75 upon request

• Rated frequency: 50 Hz or 60Hz

Standard Voltage Transformer (with voltage source)

SVT series standard voltage transformers are used as reference transformer for voltage transformer measurement. The secondary voltage output is 100v, 100/√3V, 110V and can be replaced by 110/√3V, 220V or 240V upon request.

Main Technical Specification

  1. Rated primary voltage (kV): 6, 10, 15, 22, 36 (upon request)
  2. Rated secondary voltage (V): 100, 100/√3, 110
  3. Accuracy: class 0.05, class 0.1
  4. Rated frequency: 50 Hz
  5. Rated load (cosφ=1): 0-0.2VA
  6. Voltage working range: 20-120% rated voltage value
  7. Net weight 120 (approx.)
Large Current Cable

Our large current cable is mainly used as a core-through cable during current transformer test. Meanwhile it can also be used in other large current experiment. It uses φ0.1mm non-oxygen copper wire after twisting. Its surface is woven by soft cotton, which features in sufficient cross-section, soft cable and low internal resistance.

Normal configuration    

Quantity             Length          Specification

2000A                        1pc                     3m                400mm2

1000A                         1pc                     5m               200mm2

500A                           2pcs                    1.5m           100mm2

250A                           2pcs                    1.5m            50mm2

100A                           2pcs                    1.5m            20mm2

Note: specification and length of high current cable can be required by the customer.