Technology Literature

How to make test with turn ratio tester

The turn ratio tester is a kind of alternating current low voltage test that helps to find out the ration of high voltage winding to all other windings with no load. It is a single and three phase transformer testing that can be used to measure the excitation current, turns ration and the polarity of windings in both single and three phase distribution. Actually, it can be tested phase by phase in the current, potential and also the tapped transformers as well. Primarily, the turn ratio tester is a device used to perform testing on every tap of each winding as well as measure the turns ration in between the windings.

Most probably, these ration measurements can be conducted in the entire tap positions that should be calculated by dividing induced reading voltage into applied voltage value. However, this ratio test is specifically made on three- phase transformers, but it can be taken up once at a time with a three phase turn ratio tester until all the three phase ratio measurements are completed.

Turn Ratio Tester

Usually, the turn ratio tests can be made with turn ratio tester in the following ways that include:

1. Isolate the device to apply working on grounds to all the incoming and outgoing cables.
2. Connect the H designated three phase test lead at one end and ensure that it is properly notch the lines up.
3. Now, you connect the X designated three phase test at other end and make sure whether it lines up properly.
4. Connect all H1, H2, H3 test to the respective H1, H2, H3 transformer bushing or terminal. If H0 terminal or bushing is present, you can connect H0 test lead.
5. After that connect X1, X2, X3 test leads to respective X1, X2, X3 transformer bushings or terminal and also connect X0 as well.
6. Perform the measurement of turns ration for all tap positions.
7. Confirm the measured ratio is within 0.5% of calculated rations.


Contact: Steven Cao

Phone: +86 15097752737

Tel: +86-0312-5308005


Add: Building2# torch high-tech park baoding city,China