NR Electric PCS-9611, Instruction Manual

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3 Operation Theory
PCS-9611 Feeder Relay
3-4
Date: 2014-04-08
phase-to-phase voltages are greater than the voltage setting of the voltage blocking element
of the frequency protection if the stage 4 under-frequency protection is enabled and ready for
operating.
36. The frequency is greater than the setting of the stage 1 over -frequency protection and all the
phase-to-phase voltages are greater than the voltage setting of the voltage blo cking element
of the frequency protection if the stage 1 over-frequency protection is enabled and ready for
operating.
37. The frequency is greater than the setting of the stage 2 over -frequency protection and all the
phase-to-phase voltages are greater than the voltage setting of the voltage blocking element
of the frequency protection if the stage 2 over-frequency protection is enabled and ready for
operating.
38. The rate-of-change of frequency is greater than the setting of the stage 1 frequency
rate-of-change protection if the stage 1 frequency rate-of-change protection is enabled.
39. The rate-of-change of frequency is greater than the setting of the stage 2 frequency
rate-of-change protection if the stage 2 frequency rate-of-change protection is enabled.
40. The rate-of-change of frequency is greater than the setting of the stage 3 frequency
rate-of-change protection if the stage 3 frequency rate-of-change protection is enabled.
41. The rate-of-change of frequency is greater than the setting of the stage 4 frequency
rate-of-change protection if the stage 4 frequency rate-of-change protection is enabled.
42. If anyone the binary inputs of the mechanical protections is energized if the corresponding
mechanical protection is enabled.
43. All the phase currents are less than the setting of the undercurrent protection multiplied by
1.10 if the undercurrent protection is enabled and the relevant circuit breaker is closed.
44. Anyone of the phase currents is greater than the setting of the dead zone protection
multiplied by 0.95 if the dead zone protection is enabled and the relevant circuit breaker is
opened.
If the auto-recloser is enabled, the FD (Fault Detector) element will reset to normal operation
status after the auto-recloser is reset; otherwise, the FD element will reset 500ms later after the
last one of the above items is reverted.
3.3 Overcurrent Protection
3.3.1 Definite Time Overcurrent Protection
The overcurrent protection in this relay provides a six-stage phase overcurrent protection with
independent definite time characteristics. Each stage can be enabled or disabled independently
by the logic settings respectively. All overcurrent element, directional element, voltage control
element and harmonic blocking element settings apply to all three phases but are independent for
each of the first four stages. The last two stages are pure overcurrent protections. Configuring the