Identical
Delay Time
settings should be configured in the “Testing After Initial Trip”
section for all configured tests in all the series connected devices that are set up for the
PulseFinding technique with TCC shifting. For example, if there are three configured
tests and device 1 has a
Delay Time
setting of 2 seconds for Test 1, 5 seconds for Test 2,
and 10 seconds for Test 3, then, devices 2 and 3 should also have
Delay Times
settings
of 2 seconds for Test 1, 5 seconds for Test 2, and 10 seconds for Test 3.
Also, the Test 1
Delay Time
setting must be less than the Test 2 Delay Time, which
must be less than Test 3
Delay Time
setting.
Follow these steps to use TCC shifting with the PulseFinding technique.
STEP 1.
Configure the “Initial Trip” section for each direction of the selected General
Profile.
STEP 2.
Check the PulseFinding technique check box.
STEP 3.
Check the TCC Shifting check box.
STEP 4.
Set the
Test TCC Hold
setpoint.
This setting must be shorter than the shortest
Delay Time
setting in the
“Testing After Initial Trip,” “Overcurrent,” and “IFS Element” sections. It must
also be 100 ms longer than the longest
Definite Time Min. Time
settings for
TCC for Test Sequence Test 1 through Test 4
For this example, faults will reinitiate after five cycles. So, the
Test for
TCC Hold
setting time should be a minimum of 84 ms + 100 ms, or 184 ms.
Therefore, the shortest
Delay Time
setting for Testing After Initial Trip must
greater than or equal to 185 ms. That also defines the longest
Definite Time
Min. Time
setpoint as less than or equal to 84 ms.
STEP 5.
Set the
Inverse Segment
setpoint to “none” for each of the TCC for Test
Sequence Test-n sections.
STEP 6.
Set the
Definite Time Min. Time
setpoint as indicated in Step 4.
STEP 7.
Set the “Testing After Initial Trip,” “Overcurrent,” and “IFS Element “sections
making sure the
Delay Time
settings are set as indicated in Step 4.
Sensitive Earth
Trip on Current Spikes
When enabled, the
Sensitive Earth Trip on Current Spikes
setting causes the
IntelliRupter fault interrupter to trip and immediately lock out if the user-specified
number of current spikes occurs within the user-specified time period. The
Current
Spike
counter is incremented each time current goes above the
Sensitive Earth Min
Trip
value. The timer is a constant rolling window, so when no current spikes occur
within the user-specified trip within time, the
Current Spike Counter
element is fully
reset. The
Sensitive Earth Current Spike Trip
element and the
Sensitive Earth
Overcurrent
element can both be enabled and will operate independently of each other.
(Default: Disabled) See the
Minimum Time Between SEF Current Spikes
setting on
the
Setup>Protection>Advanced Setup
screen.
S&C Instruction Sheet 766-530 59
Protection Setup
