doble TDR9000, User Manual, Page: 393 / 454

72A-1898 Rev. A 11/01 F-1
Monday
, November 26, 2001 1:09 pm
Appendix F. Glossary
Slow Close
A manual operation that consists of the operating
mechanism, usually by a hydraulic jack, to
measure contact insertion. Contact insertion being
the point of travel at initial contact make to the
final resting place of the contacts in the fully closed
position.
First Trip or First Close
When a circuit breaker is not operated for a long
period of time, whether in service or out, the
lubrication for mechanical components may suffer
changes its viscosity resulting in a loss of
lubricating ability. This may cause an in-service
breaker to be slow in tripping or an out of service
breaker to be slow in closing.
By connecting the TDR9000 to the in-service
breaker, phase currents, trip and close coil
currents, DC battery supply and auxiliary contacts
can be monitored as the recording is started by an
external signal. This provides data that indicates if
the circuit breaker operated properly when
prompted. If not, data analysis indicates the
problem so that appropriate maintenance can be
applied. This is useful, as often times the breaker
operates properly on a second trip operation
(out-of-service), as the lubricant has been
exercised.
Capacitor The TDR9000 T9330 Capacitance Measurement
option allows the testing of grading capacitors to
determine their picofarad value.
Refer to ”Open-Gap Grading Capacitor”
on page A-18 for an explanation of their function.