Safety First - doble TDR900 User

Sectional test: Sometimes called a live tank test or an EHV test. This is a test which
looks at individual breaks per phase. Each individual moving second of
the breaker can be timed separately.
Off-line test: Off line is the usual state for a breaker to be in when performing a breaker
timing test; connections can be made at line terminals. Appropriate safety
precautions should have been taken to ensure safety of personnel and
equipment. Safety documentation should be in place authorizing the tests
to be performed.
On-line test: The breaker is energized and/or carrying load when it operates. Do not
make any connections to any line terminal as system voltages appear on
those terminals. A "First trip" test requires the breaker be energized when
it trips.
Motion: Motion is measured through a transducer; this is a record of the movement
of the mechanical part of the breaker as it opens or closes the breaker; also
called travel. Motion can be used to give the velocity of the breaker's
moving parts.
1.4

Safety First

Safety of personnel, breaker and test equipment is of paramount importance when
performing any sort of timing test.
Please be sure to read and follow the safety instructions pertinent to your location before
making any connections or performing any tests.
Safety is discussed in more detail in Section 3.1.
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Doble TDR900 User Guide
72A-2612-01 Rev. A 09/06