Vanguard CT-7500 - Manual (Page 66)

MODEL CT-7500 OPERATING INSTRUCTIONS
60
Rev 2 Jan 2001
10.0 Running CT-7500s in Tandem
For timing application requiring more than 12 timing contact channels, the user can use two or
more CT-7500s to time a circuit breaker. A typical application is to use a CT-7500-12 and a CT-
7500-6 to time a 18 contact ATB. To time this circuit breaker, the user can use the following steps:
Connect the CT-7500-12 to phase A and B of the circuit breaker.
Connect the CT-7500-6 to phase C on the circuit breaker.
Connect the CT-7500-12 initiate cable to the breaker control circuit. The CT-7500-12 will
operate the circuit breaker.
Connect the external trigger cable of the CT-7500-6 to the OPEN coil for the OPEN test or
CLOSE coil for the CLOSE test. The CT-7500-6 will operate as the slave device.
Set the CT-7500-6 to start a test using “External Trigger”.
Set the CT-7500-12 to start a test using “Internal Trigger”.
Press the “START” key on the CT-7500-6 to start the sequence then press the “START”
key and hold the “ARM” switch on the CT-7500-12.
The CT-7500-12 will operate the circuit breaker and start the timing sequence; The CT-7500-6 will
start its timing sequence as soon as it senses the voltage applied to the breaker coil.
The timing report of the CT-7500-12 will show the contact time for phase A and B. The timing
report of the CT-7500-6 shows contact time for phase C.
If the user down-loads the test results of both the CT-7500s to the PC, the user then can combine
the 2 test reports to generate a 18 channel test report.