Vanguard CT-7000 S3 - Manual (Page 19)

REV 1 CT-7000 S3 USER’S MANUAL
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3.1.3. Online Timing Connections (with optional Online Timing feature)
In addition to the conventional off-line timing mode, the CT-7000 S3 also offers an optional
three-phase “on-line” timing mode. In this mode, the CT-7000 S3 captures the breaker’s trip or
close time, the trip/close coil current “fingerprint”, the battery supply voltage, and auxiliary
switch times 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 breaker make/break as detected by
a AC clamp-on current sensing probes. Trip/Close current waveforms are also captured by an
external clamp-on DC current probe.
The “on-line” timing mode can detect a breaker’s operating conditions with little or no down
time. In this 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 “on-line” 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.
The CT-7000 S3 On-Line timing mode requires the use of 3 AC current sensors (provided with
the Online Timing Option, Part no. 9021-OT) to monitor the contact time phases A, B, and C.
The Open and Close coil current is monitored by using the provided DC current sensor
(provided with the Online Timing Option, Part no. 9021-OT). The On-Line timing mode requires
the External trigger to be connected. Please see Figure 7 for the On-Line timing test
connections.
Figure 6. On-line Timing Probe Set (Part No. 9021-OT)