AC-PRO
®
& AC-PRO-II
®
B-292 Secondary Injection Test Set Instruction Manual Rev 1.1
www.utilityrelay.com
Page 14
4.10
Instantaneous (I) Pick-Up Test
To test Instantaneous pick-up:
1)
Hold down the Current Preset (13)
while adjusting the Amp Coarse (14)
and Fine (15) pots to 90% of the
calculated I
SPU.
2)
Set the Phase selector (11) to either
Phase A, B or C.
3)
Push the Start (5) button but leave the
test current on only long enough to see
if an I trip occurs. If the current is left
on long enough a LT or ST trip will
occur. If ST is on, it is best to
temporarily turn it off.
An I trip should NOT occur.
4)
Hold down the Current Preset (13)
while adjusting the Amp Coarse (14)
and Fine (15) pots to 110% of the
calculated I
SPU.
5)
Push the Clear (8) button to reset the
Timer (6) to zero.
6)
Push the Start (5) button.
An I trip should occur. The test set
current will stop and the Timer (6) will
freeze displaying the trip time.
7)
Verify that the AC-PRO or AC-PRO-II
saved the proper last trip data.
8)
Repeat for the other two phases
if desired.
4.11
Calculate Ground Fault (GF) Pick-Up
Secondary Current
Calculate the GF secondary pick-up current
(GF
SPU
) as follows:
For 1-Amp AC-PRO or AC-PRO-II:
GF
SPU
= GF Pick-Up
CT Primary Rating
Example: If the CT Primary rating is 1600 and
the GF pick-up is 1200 amps, then:
GF
SPU
= 1200 = 0.75 amp
1600
For 0.5 Amp AC-PRO or AC-PRO-II:
GF
SPU
= GF Pick-Up X 0.5
CT Primary Rating
Example: If the CT Primary rating is 1600 and
the GF pick-up is 1200 amps, then:
GF
SPU
= 1200 X 0.5 = 0.38 amp
1600
Note: If the Neutral CT Secondary Rating is different
than 1.0 or 0.5, use the 0.5 example above and replace
0.5 with the specific Neutral CT Secondary Rating.
