doble TDR9000, User Manual, Page: 225 / 454

TDR9000
™
Circuit Breaker Test System User’s Guide
72A-1898 Rev. A 11/01 A-25
Monday
, November 26, 2001 1:09 pm
Figure A.26 shows what happens when the diagram is simplified and
analyzed at the moment when contact #2 closes and contact #1 is still
open.
Figure A.26 Capacitance-to-Ground:
Contact #2 Closed, Contact #1 Open
When contact #2 closes, the potential at point A goes from +V
s
to zero.
Consequently, to simplify the analysis, replace the closing of contact #2
with a voltage source, which represents a step-down function.
Excluding the Instrument power supply (S) from the circuit, since it has
no effect on the transient process, and redrawing the diagram, it appears
as shown in Figure A.27.
Figure A.27 Capacitance-to-Ground:
Contact #2 Closed, Contact #1 Open (Simplified)
R
6
1
R
6
2
A B
C
1
C
3
C
C
2
Contact #1 Contact #2
A
C
3
C
1
B
R
g
1
R
g
2
C
2
C