TRENDnet BE1-87G - Manual (Page 35)

5-8 BE1-87G - Testing And Setting
NOTE
If option B (current operated) targets are specified, the target is only operable when a
minimum of 0.2 ampere is present in the output circuit (terminals 1 and 10).
Phases B And C, Trip And Dropout Test
Step 1. If the relay is a 3-phase relay, repeat steps 1 through 7 for phases B and C.
Target Test
If relay is equipped with targets, check for correct operation of each phase when relay is tripped, and for manual
reset.
Auxiliary Output Test
If an Auxiliary output (Option 3-2 or 3-3) is present, check outputs at terminals 2 and 5 (either NC or NO as
specified) when relay is tripped.
Push To Energize Output Test
If a PUSH TO ENERGIZE switch (Option 2-C) is present, verify correct operation by depressing the switch and
observing that the output and auxiliary relays cycle (terminals 1 and 10 and terminals 2 and 5 respectively.)
Power Supply Status Output Test
Step 1. If power supply status output (Option 3-6) is present, verify correct operation by applying appropriate
voltage to the power input, placing the unit in a powered-up condition, verifying that the power supply
status output contacts are energized open (terminals 2 and 5).
Step 2. Remove input power and verify that the power supply status output contacts close.
SETTING THE RELAY
General
This paragraph provides recommendations for selecting the current sensitivity switch setting. Figures 5-4 and
5-5 show how this setting corresponds to the operating current pickup over the restraint current range.
Assuming that the CTs on both sides of the zone (generator, motor or reactor) perform identically, operating
current will be equal to zero. The sensitivity setting serves to accommodate dissimilar CT performance, resulting
from differences in CT quality, burden, and core remanence.
During normal operation, the pickup on the flat part of the operating characteristics (refer to Figures 5-4 and 5-5)
must exceed the difference in steady-state CT errors. The relay must also override the error differences in the
presence of dc components developed by external faults or switching. Currents will be offset during external
faults on generator applications, during motor starting, and during switching of shunt reactors.
Out-of-phase synchronizing of machines will also produce offset components. These so-called dc components
will produce significant CT saturation. For high-current faults, the relay relies on the 50% slope characteristic
to override large operating currents. Significant operating current can also be developed at restraint levels that
fall on the flat part of the characteristic if the offset component persists. The sensitivity setting needs to be above
this operating current.