Application; Overview - NDB Technologies NDB-DOC-3 User Manual

4. Application

The NDB-DOC-3 is a test instrument designed to measure the status of de-ener-
gized distribution transformers. It determines the presence of short circuits or open
circuits in the transformer primary winding and also short circuits on the second-
ary winding. The NDB-DOC-3 uses DC resistance and AC impedance test methods
to test a wide range of distribution transformer configurations. The NDB-DOC-3 is
designed to be operated without needing to disconnect the transformer secondary
windings from their loads. Please note, partial shorts, or short shorts that only ap-
pear under high voltages may not always be detected by the NDB-DOC-3. If used on
secondary winding to perform an open winding test, user must stand clear of the
primary high voltage terminals while testing.

5. Overview

This section of the user manual describe the principal features of the NDB-DOC-3.
Display
Transformer power
rating selection
buttons
Power and battery
level indicator
Power button
N D B - D O C - 3
Test lead connector
Buzzer
- U s e r M a n u a l
6
Result indicator for:
• Short circuit
• OK circuit
• Open circuit
Transformer primary
voltage rating adjust-
ment buttons
Start test button
Winding configuration
type selection button