Owner's manual

REV 2 CT-7500 S2 USER’S MANUAL
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3.2.4. Running CT-7500 S2’s in Tandem
Two or more CT-7500 S2’s can be used to time a circuit breaker that requires more contact
channels than those available on the single CT-7500 S2 unit. The example below shows how to
use two CT-7500-6 S2’s (6 channels each) in tandem to create a 12 contact timing apparatus.
Use the steps below to configure the CT-7500 S2’s:
a. Connect the Master CT-7500-6 S2 to phase A and B of the circuit breaker.
b. Connect the Slave CT-7500-6 S2 to phase C of the circuit breaker.
c. Connect the Master CT-7500-6 S2’s initiate cable to the breaker control circuit. This unit
will operate the circuit breaker.
d. Connect the Slave CT-7500-6 S2’s external trigger cable to the OPEN coil for the OPEN
test and CLOSE coil for the CLOSE test. This unit will operate as a slave device.
e. Start running a test from the Slave CT-7500-6 S2 using the EXTERNAL TRIGGER option.
f. Run a test from the Master CT-7500-6 S2 Master using the INTERNAL TRIGGER option.
The Master CT-7500-6 S2 will operate the circuit breaker and start the timing sequence. The
Slave CT-7500-6 S2 will start its timing sequence as soon as it senses the voltage applied to the
breaker coil. The timing report of the Master CT-7500-6 S2 will show the contact time of phase
A and B. The timing report of the Slave CT-7500-6 S2 will show the contact time for phase C. If
the results are downloaded to a PC using the included software, the two reports can be
combined to generate a 12-channel test report.
Figure 19. Typical Initiate and Trigger Connections for Operating Two CT-7500 S2's in Tandem