To Next Page

To Previous Page

AVTMTTR100-ENG Rev 6 Nov 2015

When testing DC winding resistance, it is important that reliable connections are

made with the transformer being tested. Measuring time will vary depending on

size and vector group of the transformer being tested.

NOTE: The polarity indicated by the TTR100 is relative to the manner in which it

is connected to the device under test.

Single-Phase, Two-Winding Transformers

Perform the following setup procedure for single-phase, two-winding

transformers:

1. Connect the H and X test cables to the respective H and X receptacles of the

test set. Make sure that the connectors are fully engaged into the receptacles.

2. Connect the ground lead of the H test lead set to a low-impedance earth

ground. Connect the clips marked H1 and H2 of the test lead to the

corresponding (high-voltage winding) terminals of the transformer under test.

3. Connect the clips marked X1, X2 of the test lead to the corresponding (low-

voltage winding) terminals of the transformer under test. Keep X3 clear of

ground and test setup. Figures 5-1 and 5-2 show test setups for single-phase

transformers. Figures 5-3 and 5-4 show test setups for regulators. These and

additional connection diagrams are found within the TTR100.

Distribution Transformers with Two Secondary Windings

The TTR100 may test the turn ratios of both distribution transformer secondary

windings simultaneously. Perform the following setup procedure for single-phase

distribution transformer with two secondary windings:

1. Connect the H and X test cables to the respective H and X receptacles of the

test set. Make sure that the connectors are fully engaged into the receptacles.

2. Connect the ground lead of the H test lead set to a low-impedance earth

ground. Connect the clips marked H1 and H2 of the test lead to the

corresponding (high-voltage winding) terminals of the transformer under test.

3. Connect the clips marked X1, X2 and X3 of the test lead to the corresponding

(low-voltage winding) terminals of the transformer under test when testing

both halves of secondary winding (X1 – X2 and X3 – X2).

When testing full secondary winding (X1 – X3), connect X1 lead to X1

terminal, connect X2 lead to X3 terminal (X3 lead is not used in such test, and

it should be kept clear of ground and other terminals). Remove the ground

connection to X2 terminal.

Megger AVTMTTR100 User Manual

Questions and Answers: