9137200997 Rev D BE1-51 Tests and Adjustments 5-7
Instantaneous Overcurrent Pickup Test
This test checks the minimum overcurrent pickup points for Instantaneous 1 and (if present)
Instantaneous 2 outputs.
Step 1. Perform the preliminary instructions.
Step 2. Reconnect the test setup to the INST 1 output terminals 2 and 10 as shown in Figures 5-1
through 5-4. Note that the timer may be removed from the test setup at this time.
Step 3. Set the TAP selector to A.
Step 4. Turn the front panel INST 1 control fully CCW to establish a pickup point of 1 times the TAP
selector A setting.
Step 5. Slowly adjust the test set, increasing the overcurrent threshold toward the value of the front
panel TAP selector A setting until the Instantaneous 1 output relay energizes.
RESULT: If target Type A or B is present:
(a) The front panel FUNCTION-INST 1 target (if present) will trip.
(b) The appropriate front panel ELEMENT target A, B, or C (if present) will trip.
Step 6. Remove input current. Record the test set current setting.
RESULT: The recorded value should be equal to or less than the front panel TAP selector A
setting for the minimum overcurrent pickup point for the instantaneous 1 overcurrent element.
Step 7. Reset the relay front panel targets (if present).
Step 8. Turn the front panel INST 1 control fully CW to establish a pickup point of 40 times the front
panel TAP selector A setting.
Step 9. Adjust the test set to approximately 35 times the front panel TAP selector A setting.
Step 10. Slowly adjust the test set further toward an overcurrent threshold of 40 times the front panel
TAP selector A setting until the instantaneous 1 output relay energizes. Do not disturb this
setting.
RESULT: If target Type A or B is present:
(a) The front panel FUNCTION-INST 1 target (if present) will trip.
(b) The appropriate front panel ELEMENT target A, B, or C (if present) will trip.
Step 11. Record the current reading. Remove input current (the front panel TIMING indicator should
extinguish).
RESULT: The recorded value should be greater than 40 times the front panel TAP selector A
setting for the maximum overcurrent pickup point for the instantaneous 1 overcurrent element.
NOTE
Due to delays inherent in the test equipment, the time delay may appear to
exceed these limits. This concludes the timed output test.
Relays having instantaneous overcurrent option 1-1 or 1-2 only proceed to the
Instantaneous Overcurrent Pickup Test.
NOTE
For relays having three-phase sensing (Sensing Input Types G or V), only a
single input phase is connected since this is sufficient for a complete test of the
instantaneous overcurrent sensing and output.
For relays that include neutral sensing (Sensing Input Types H, I, V, or X), this
test includes reconnecting the test output to the neutral sensing terminals for
testing the instantaneous 1 output during neutral sensing.
Courtesy of NationalSwitchgear.com
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