Vanguard CT-7000 S3 - Manual (Page 21)

REV 1 CT-7000 S3 USER’S MANUAL
16
3.1.4. Dual Ground Connections (with optional Dual Ground feature)
With the optional dual ground testing mode, the CT-7000 S3 can measure a CB contact time
with ground being applied to both sides of the bushings. The clamp-on probe is connected to
one side of the CB safety ground straps, and an AC signal is coupled to this strap. A sensor on
the probe will detect a change in the induced AC signal when the CB contact is opened or
closed.
The CT-7000 S3 Dual Ground test mode requires the use of the Vanguard Dual Ground Current
Probes (provided with the Dual Ground option, part no. 9021-DG). Up to 3 timing channels are
available with the Dual Ground option. Only timing channels 1, 2, and 3 are used for this mode
(see Figure 8).
Figure 8. Typical Connections for Optional Dual Ground Testing Mode
NOTE
Transducer channels, voltage monitoring channels, and the initiate circuit are
connected the same as the regular time travel test mode.