BE1-51/27R - Tests And Adjustments
5-7
NOTE
For relays having three-phase sensing (sensing input type B, C, R, or S) only a single
input phase needs to be connected, since this is sufficient for a complete test of the time
delay. For relays that include neutral sensing (sensing input types E, F, U, N, Y, or Z),
this test includes reconnecting the test output to the neutral sensing terminals for testing
the timed output during neutral sensing.
Step 16. Adjust the front panel CAL (NEUTRAL) control fully CW to allow measurement of the actual
overcurrent pickup point at the A setting of the front panel TAP (NEUTRAL) selector. Note that
the front panel TIMING (NEUTRAL) indicator will extinguish. Do not disturb this setting.
Step 17. Slowly increase the current toward the value of the front panel TAP (NEUTRAL) selector A setting
until the front panel TIMING (NEUTRAL) indicator illuminates. Do not disturb this setting.
Step 18. Record the current reading and remove input current.
RESULT: The recorded value should be within ±5% of the front panel TAP (NEUTRAL) selector
A setting for the neutral minimum overcurrent pickup point for the time overcurrent.
Step 19. Set the front panel TAP (NEUTRAL) selector to J.
Step 20. Slowly adjust the test set, increasing the overcurrent threshold toward the value of the front panel
TAP (NEUTRAL) selector J setting until the front panel TIMING (NEUTRAL) indicator just illumi-
nates. Do not disturb this setting.
Step 21. Record the current reading and remove input current.
RESULT: The recorded value should be within ±5% of the front panel TAP (NEUTRAL) selector
J setting for the neutral maximum overcurrent pickup point for the time overcurrent element.
Timed Output Test
This test checks the accuracy of the time overcurrent characteristic delay.
Step 1.
Verify that the preliminary instructions have been performed.
Step 2.
(Timing type Z1, Z2, or Z3 only.) Select the desired time current characteristic curve.
Step 3.
Set the front panel TAP selector to B.
Step 4.
Adjust the front panel TIME DIAL to 20.
Step 5.
Adjust the test set for an overcurrent threshold of precisely 5 times the front panel TAP selector
B setting, as measured on the ammeter.
Step 6.
Apply input current to the relay and initiate the test setup timer.
Step 7.
Observe that the appropriate front panel TIMING indicator illuminates and when the time delay
ends that the timed output relay is energized.
RESULTS:
(1)
The appropriate front panel TIMING indicator extinguishes.
(2)
The test setup timer stops. (Record count for use in Step 9.)
(3)
If target type A or B is present:
(a)
The front panel FUNCTION-TIME target (if present) trips.
(b)
The appropriate front panel ELEMENT target A, B, or C (if pres-
ent) trips.