Vanguard CT-8000 - Manual (Page 8)

CT-8000 USER’S MANUAL REV 2
3
Trip/Close Current Monitoring
A built-in Hall-effect current sensor records the Trip/Close current level and duration. The
breaker’s operate-coil current waveform duration (effectively, a performance "fingerprint" or
"current profile") can be used as a diagnostic tool for analyzing a breaker’s performance.
Breaker Stroke and Velocity
Three digital travel transducer channels are available on the CT-8000 for measuring circuit-
breaker velocity, stroke, over-travel, and bounce-back. Unlike other transducer types, the
digital transducer requires neither calibration nor setup. A breaker’s contact-velocity is
calculated based on the contact’s travel distance over a period of time. A special feature is also
available to “slow-close” test a breaker and obtain a test result report.
Dynamic Contact Resistance
Using a 200-ampere, built-in, DC power supply, the CT-8000 can also perform dynamic-
resistance tests. One channel is available for performing a dynamic contact resistance test. The
resistance measuring range is from 1 micro-ohm to 1,999 micro-ohms. Using this test, the
contact resistance can be monitored during circuit-breaker operation. This important feature
can help detect circuit-breaker contact erosion or other contact problems that cannot be
detected in static resistance tests. The CT-8000 can also be used as a 200-ampere micro-
ohmmeter to test circuit-breaker contact resistance and bus connections, or can be used for
other applications where a low-resistance measurement is required.
Resistor Type Transducer Input
One resistor type input channel is also available on the CT-8000. This input channel allows the
unit to measure circuit-breaker motion by directly interfacing with resistive type transducers.
The transducer resistance ranges from 200 ohms to 10K Ohms.
Breaker Initiate Features
A built-in solid-state initiate device is used to operate a breaker from the CT-8000. The
operational modes include Open, Close, Open – Close, Close – Open, and Open – Close – Open.
Multiple operations, such as Open – Close and Open – Close – Open, can be initiated by using
programmable delay time or by sensing a breaker’s contact condition.
Internal Test Record Storage
The CT-8000 can store up to 150 test records in Flash EEPROM. Test records can be retrieved
and printed on the built-in thermal printer, or they can be transferred to a PC via the unit’s RS-
232C or USB interface.
Internal Breaker Test Plan Storage
The CT-8000 can store up to 99 circuit-breaker test plans. Test plans are comprised of all circuit-
breaker performance specifications (stroke, velocity, and contact time). A test plan can be used
to immediately test a circuit-breaker. A pass/fail report is then generated by comparing actual
performance with the specifications in the stored test plan. Test plans can also be generated on
a PC and transferred to the CT-8000 via the unit’s RS-232C or USB interface.