BE1-50/51M-222 General Information
1-5
Harmonic Response
BE1-50/51M-222 harmonic rejection is illustrated in Figure 1-4.
Figure 1-4 shows that a relay set for one ampere pickup would pickup at
0.96 ampere on a current containing 40% seventh harmonic. This
corresponds to a ten-to-one rejection ratio. Other conditions may be
evaluated in the same manner.
Figure 1-4. Harmonic Response
INST Characteristics
BE1-50/51M-222 instantaneous characteristic curves are similar to
standard electromechanical instantaneous units. However, the time to trip
for ground applications is slightly longer than that for phase applications to
allow time to power-up the relay. Longer trip time for ground applications
is beneficial because it helps to avoid nuisance trips.
For phase applications, the maximum time to trip is 3.5 cycles at a pickup
multiple of 1.0, and 1.5 cycles at a pickup multiple of 3.0. The
corresponding times for ground applications are 4.5 and 1.75 cycles.
Figure 1-5 shows the instantaneous characteristic curves for maximum
time to trip.
Additional delays of 0.1, 0.2, or 0.3 seconds may be added with internal
switches SW8-2 and -3. These delays apply to both phase and ground
applications. Closing switch SW8-2 provides an additional delay of 0.1
second. Closing switch SW8-3 provides an additional delay of 0.2 second.
Closing both switches SW8-2 and -3 provides an additional delay of 0.3
second. Section 2 illustrates the location of SW8.
Time Characteristics
Nine inverse time functions and one fixed time function can be selected by
a front panel switch.
Summary of Contents for BE1-50/51M-222
Page 29: ...BE1 50 51M 222 Installation 4 2 Figure 4 1 Outline Dimensions C1 Case ...
Page 30: ...BE1 50 51M 222 Installation 4 3 Figure 4 2 Panel Drilling Diagram C1 Case ...
Page 32: ...BE1 50 51M 222 Installation 4 5 Figure 4 4 DC Control Connections ...
Page 33: ...BE1 50 51M 222 Installation 4 6 Figure 4 5 BE1 50 51M 222 Overcurrent Relay Rear View ...
