Vanguard CT-8000 - Manual (Page 7)

REV 2 CT-8000 USER’S MANUAL
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1.0 INTRODUCTION
1.1 General Description and Features
The CT-8000 is Vanguard’s fifth generation, stand-alone, microprocessor-driven EHV circuit-
breaker analyzer. This easy to use analyzer is available in models with either 3 (CT-8000-3) or 6
(CT-8000-6) dry-contact inputs. Both models feature three digital travel transducer input
channels. The CT-8000 can operate either in Time-Travel analyzer mode or in Quick-Shot mode
(for on-line timing).
Quick-Shot Mode
In Quick-Shot mode, the CT-8000 captures the breaker’s trip or close time, the trip/close-coil
current “fingerprint,” and the battery supply voltage while the breaker is still in service. The
trip/close time is derived from the time of trip, or close-coil initiation, to the breaker’s bushing
current-break-or-make as detected by an AC clamp-on current sensing probe.
With a simple connection, the Quick-Shot mode can detect a breaker’s operating conditions
with little or no down time. In Quick-Shot mode, the first trip operation time of the breaker is
captured. If a breaker has been in service for a long period of time and sitting in close position,
the first trip time of the breaker may be slow possibly due to a sticky mechanism. The Quick-
Shot mode is very useful in such cases because traditional breaker timing may not detect this
condition since several operations may have occurred before the first timing test is conducted.
Conventional Time-Travel Analysis Mode
In Time-Travel mode, the CT-8000 can fully analyze a circuit-breaker’s performance by testing
the contact time, stroke, velocity, over-travel, and contact wipe. Contact-motion analysis can be
performed for all breaker contact operations (Open, Close, Open – Close, Close – Open, and
Open – Close – Open). The CT-8000 S2’s timing window is selectable between 1-second, 10-
second, or 20-second periods. The 10-second and 20-second timing windows are ideal for
timing long duration events such as circuit-switcher contact testing.
Contact Timing Inputs
Dry-contact input channels are used for timing breaker contacts. Each contact input channel
can detect main contact and insertion-resistor contact times in milliseconds and cycles.
Voltage Monitoring Inputs
One analog voltage input channel, designated as V1, is dedicated to monitoring a circuit-
breaker’s DC power supply or coil voltage (0 – 255 volts, DC or peak AC). A second voltage input
channel, designated as V2, is dedicated to detecting the voltage on/off status (presence or
absence) of an A/B switch.