Testing Static Trip II
TM
Devices
1 4
NOTE
The illumination of the “PICK-UP” light indicates that the time
delay has started. If the current drops slightly, the light will go
out, the timing circuit resets instantly and timing will start over
upon the next appearance of triggering.
The static trip level sensing circuits have a very slight amount
of hysteresis. That is, the pick-up and drop-out points of the
circuit are very nearly but not exactly the same value If the
input current is modulated in amplitude the pick-up light will
flash ON and OFF, and the timing circuit can never time out.
Long Time Pick-Up Test
1.
Leave the red and black banana plugs disconnected. To
test phase 1 connect the green plug to terminal 1 and the
white plug to terminal 9. Connect the black pin plug to
TP-1 and the yellow pin plug (TP-3) to terminal TP-3 of
the trip device .
2.
Set LONG TIME PICK-UP on “IA.” Place the selector
switch to STATIC TRIP TEST position. Set the RANGE
switch on LOW Set the POWER selector switch to
INTERNAL, set phase selector to phase 1.
3.
Turn the other power switch to ON. The red digits of the
meters should come ON. (The alarm light may also come
ON. If so, press the STOP—alarm reset button). Press
the START push button.
4.
Slowly increase the current by rotating the INTERNAL
POWER CONTROL in a clockwise direction. This is a five
turn control arranged for 50Hz operation so a noticeable
deadband is evident at zero output and 60Hz. Increase
the current until the LONG TIME PICK-UP light comes
ON. This should be at 0.5 10%. The sampling
rate of the ammeter is such that the control must be
moved very slowly to accurately determine the pick-up
current of the trip device.
5.
Decreasing the current slightly should cause the light to
go OUT.
6.
Repeat the tests for the other phases and settings and
compare with Table 2.
Short Time Pick-Up Test
1.
Connect the yellow (TP-4) pin plug to the TP-4 terminal
of the trip device, the black pin plug to TP-1, the green
plug to terminal 1, and the white plug to terminal 9.
2.
Set LONG TIME PICK-UP on “A,” INSTANTANEOUS
fully counterclockwise, LONG TIME BAND on 6 and
SHORT TIME PICK-UP on 3X.
3. Press the START button.
4.
Slowly increase the current until the SHORT TIME
PICKUP light comes ON. This should occur at 1.5
amperes ± 10%.
5.
Repeat for SHORT TIME PICK-UP settings of 5X, 8X,
and 12X. The RANGE switch must be set on HIGH for
these tests. To avoid overheating, do not maintain the
higher currents any longer than necessary.
Ground Pick-Up Test
1.
Connect the green plug to terminal 4 and the white plug
to terminal 9, connect the black pin plug to TP-1 and the
yellow (TP-2) pin plug to TP-2 on the trip device.
2.
Set GROUND PICK-UP on the 15% dot.
3.
Press the START button and raise the current gradually
until the Ground pick-up light turns ON. This should
occur at .15 ampere ± 15%, repeat for the 25% and
other settings. See the bottom line of Table 1 for the
settings in amperes.
NOTE
If the output of the trip device is connected to the tripping
actuator of the circuit breaker, the additional current drawn
during tripping may cause confusion. Either disconnect the
actuator or set the ground time delay to its MAXIMUM to allow
time to read the meter before actual tripping occurs.
Instantaneous Pick-Up Test
There is no trigger output for INSTANTANEOUS TRIP, but
tripping of the circuit breaker and/or operation of the test set
relay will indicate instantaneous trip operation. To operate the
test set relay, the red and black banana plugs must be
connected to the trip device.
1.
Connect the green banana plug to terminal 1 and the
white one to terminal 9; the pick-up pin plugs are not
needed.
