Vanguard CT-7500 - Manual (Page 8)

MODEL CT-7500 OPERATING INSTRUCTIONS
2
Rev 2 Jan 2001
or calibrate the transducer.
The CT-7500 has a built-in initiate circuit to operate circuit breakers. Since this solid-state
circuit is controlled by the micro-processor, the CT-7500 can perform multiple operations (O-C, C-
O, O-C-O) with ease. Each Trip and Close initiate circuit is fuse protected. The user is also
required to hold the “ARM” switch during a test to complete the initiate circuit.
The CT-7500 can also store up to 200 breaker-timing test records and 45 breaker test-plans in
FLASH EEPROM. Stored timing test records can be recalled and printed or transferred to the PC.
Using the breaker test plan during a test, the users do not have to set the velocity calculating
points. The CT-7500 will also print “PASS” and “FAIL” results on test report.
2.2.1 Contact Timing Channels
A breaker's interruption of contacts is timed with the dry-contact input channels. Each channel
can detect the main contacts and insertion resistor contacts times (in millisecond and cycles).
Note
The CT-7500 can detect insertion resistors in a 10-7000 ohm range. Resistances over 7000
ohms are detected as an open contact.
2.2.2 Analog Voltage Monitoring Channel
An analog voltage input is dedicated to monitoring a breaker's dc power supply or coil voltages
(0-255 V dc or peak ac).
Note
Input voltage range is 0-300Vdc or peak AC. Reading range is 0-255Vdc.
2.2.3 Digital Voltage Monitoring Channel
One digital voltage input channel monitors voltage on/off status. Voltage threshold from 30-255
Vdc is considered as “ON” status. Voltage threshold less than 30 Vdc is considered as “OFF”
status.
2.2.4 Trip/Close Current Monitoring
A built-in Hall-effect sensor records Trip and Close coil current levels and duration. The
breaker's operate coil current waveform is graphically plotted on a printout. Current reading is also
printed in the tabulated report.
2.2.5 Travel Transducer Input Channels
Each CT-7500 has 3 digital transducer input channels. These transducer channels require
neither setup nor calibration.
2.2.6 Breaker Initiate Capability
A built-in solid-state initiate device lets users operate a breaker from the CT-7500. Operational
modes include: Open, Close, Open-Close, Close-Open, Open-Close-Open. Multiple operations