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3-2 BE1-87G - Functional Description
0
5
10
15
20
25
30
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CURRENT
(
AMPS
)
VOLTAGE(VOLTS)
0
5
10
15
20
25
30
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
CURRENT
(
AMPS
)
VOLTAGE(VOLTS)
and one ampere nominal), one transformer on each side of the protected machine, supply sensing current for
each monitored phase. The sensing currents are applied to the respective input transformers of the relay which
provide system isolation and determine the differential and sum currents. These CTs are gapped to withstand
DC offset.
Stabilizing Reactor
To minimize dissimilar performance of the system CTs, the stabilizing reactor acts as a stabilizing impedance
during external faults. Stabilizing reactors are current rated based on time and ambient temperature (refer to
Section 1, Specifications
). See Figures 3-2 and 3-3 for the stabilizing reactor impedance characteristics.
Figure 3-2. Sensing Input Range 1 (5 Ampere), Stabilizing Reactor Impedance Characteristics