DOC. MIE91093 Rev. 1.34
Page 83 of 145
. After a Close command, the test set generates a new fault
after a delay equal to TD, until N+1 tests are performed;
. After the last fault, the test set waits until it is sure that no
reclose command arrives.
. The test ends after N+1 faults have been generated.
However, the fact that actually the recloser will operate N+1
times depends upon the programmed value for the reclaim
time TD:
.. If the programmed value is
more
than the recloser setting,
then the test set will generate N+1 faults, followed by N+1
fast Close commands (because they are all new faults);
.. If the programmed value is
less
than the recloser setting,
then the test set will generate N+1 faults, followed by N Close
commands of different delays (because they are all the same
fault), and there will be no Close command after fault N+1.
The reclaim time test, that is the test that the reclaim time is
correctly set, cannot be performed directly, because the
Recloser does not have an auxiliary output that trips as it
expires. For this reason, the reclaim time is tested with two
test sequences, as follows.
.
First test
: TD is programmed greater than the Recloser’s
reclaim time TDr, for instance TD = 1.05*TDr. Program the
number of tests N foreseen by the CB’s Recloser. As the fault
arrives after the reclaim time is expired, the CB must always
close, even after N+1 faults; there is no evolution in the time
delay. This behavior confirms that faults occur after TDr has
expired. The following time diagram explains the test
evolution.
FAULT
1
CB POS
N+1
2
CLOSED
OPEN
D1
R1
>TDr