TDR9000
™
Circuit Breaker Test System User’s Guide
72A-1898 Rev. A 11/01 A-87
Monday, November 26, 2001 1:09 pm
Velocity Open
Zone 1 and 2
Velocity Open Zone 1
Velocity Open Zone 1 is comprised of the Open and Close parameters
listed above. Zone 2 is similar to Zone 1 but is totally independent of
Zone 1 (Figure A.108).
Distance – Distance The Circuit Breaker Average Velocity is calculated
between the two distances specified. Distances are
relative to the starting closed position (0.000
in/mm) of the circuit breaker (Figure A.101).
Figure A.101 Contact Open Distance – Distance
The end distance (T0) must be greater than the start
distance (FROM).
N
OTE
When selecting values for calculating Average Velocity, avoid choosing
beginning or ending distances of 0.000 in/mm. Since the circuit breaker
remains in those positions for a relatively long period of time, incorrect
Average Velocities are calculated.
Distance – Time The Circuit Breaker Average Velocity is calculated
between the distance specified and a time after the
circuit breaker mechanism passes the specified
point. Distance is relative to the starting closed
position (0.000 in/mm) of the circuit breaker
(Figure A.102).
Figure A.102 Contact Open Distance – Time
Starting closed position (start of test)
From
Distance
Zone 1
To
Distance
Final Open
Starting closed position (start of test)
From
Distance
Zone 1
To
Time
Final Open
Time (ms)
10 20 30 40 50 60