Megger TTR20, Instruction Manual

Page: 19 / 60

AVTMTTR20 Rev 4 Dec 2015
11
4
SETUP, CONNECTIONS AND OPERATION
General Instructions
When testing high-voltage transformers, caution must be used at all times and all
safety precautions followed. Read and understand all safety information
contained in Section 2, Safety.
F
WARNING
Ensure that the transformer to be tested is completely de-energized.
Check every winding. Ensure that all terminals of the transformer are
disconnected from line or load at the transformer. For some
transformers, connections to ground may be left in place.
Never interchange connections between the high- and low-voltage
transformer terminals. Failure to observe proper connections will result
in a safety hazard and may result in damage to the test set or
transformer.
Check that a lead set connected is labeled for TTR20 test set operation.
The TTR20 has been designed to test a variety of transformers, such as: Single
phase, Three phase (one phase at a time), CTs, PTs and Voltage Regulators.
Do not leave the TTR20 test set exposed below -5
0
F or above 130
0
F (-20
0
C or
above 55
0
C) for more than 2 hours. Such conditions will lead to shortened
service life of batteries.
When storing the TTR20 at temperatures below -55
0
F or above 140
0
F (-20
0
C or
above 55
0
C), remove the batteries. See Battery Replacement for detail.
Transformers
The setup and connection instructions pertaining to ratio, polarity, and phase
relation assume that the transformer under test, connections, and terminal
markings comply with the requirements of ANSI C57.12.70-2011
American
National Standards Terminal Markings and Connections for Distribution and
Power Transformers
. The H leads of the test cable are the exciting leads.