Introduction:

The equipment is used to test the turn ratio accuracy, resolution and group ( including Z type) of the instrument transformer turn ratio testers with accuracy at 0.5 or below 0.05. It is composed of two parts: standard three phase PT and inductive voltage divider. The PT is used to test ratio group test function of the ratio tester, inductive voltage divider is used to test the accuracy and resolution of the ratio tester

Technical indicators:

1) Primary voltage : 200V

2) Secondary voltage: 0～200V

3) Rated load: 0VA

4) Inductive voltage divider accuracy: 0.0005%

5) Ratio Uncertainty: 3×10-6

6) Weight: 10Kg

7) Standard three phase PT accuracy: 0.05%

Functions

1. Turn ratio test by divider

Turns ratio range can be preset as the reciprocal of any value during 1.111111～0.0000001. When turns ratio is 1,2,5,10,20,50,100,200,500,1000,2000,2500, the dial scale of the inductive voltage divider should be selected as 1.000000,0.5000000,0.2000000,0.1000000,0.0500000,0.0200000,0.0100000,0.0050000,0.0020000,0.0010000,0.00050000,0.00040000. UAX rated voltage is 200V, it can work under 20%～100% of rated voltage.

2. Resolution test

Usually set the divider value during 0.1000000～0.0999900 which mean turn ratio to be 10.000～11.100. The display value of the ratio tester should obviously change when the divider set value changes.

3. straight-through test

It means the test when divider set value is 1.000000. When make this test, the primary UAB will be directly connected with secondary terminal ( a, b terminal), that is to say, UAB=Uab. It is 1/1 self-checking. But when the ratio tester is the type for which such straight test are not allowed, inductive isolated winding can be used to do 1/1 isolation test.

4. Ratio group test

The standard three phase PT can make 12 groups for group testing of the ratio tester. Turns ratio can be 10 or 100 or 1000 total 3 choices. PT each single phase error less than 0.05%

5. Z type group test

Total 10 groups(△/Z or Y/Z) for Z type, the turn ratio to be 100. PT each phase secondary winding error less than 0.05%