01-03-2013, 04:42 PM
INSTRUCTION MANUAL UNDER/OVERVOLTAGE PROTECTION RELAY GRD130 - xxxD
INSTRUCTION MANUAL.docx (Size: 375.58 KB / Downloads: 87)
Introduction
GRD130 series relays provide overvoltage and undervoltage protection for distribution
substations, generators, motors and transformers.
The GRD130 series has two models and provides the following protection schemes in both
models.
• Overvoltage and undervoltage protection with definite time or inverse time characteristics
• Instantaneous overvoltage and undervoltage protection
• Over- and under-frequency protection
• Frequency rate-of-change protection
The GRD130 series provides the following protection schemes depending on the models.
• Zero phase sequence overvoltage protection
• Negative phase sequence overvoltage protection
The GRD130 series provides the following functions for all models.
• Eight settings groups
• Configurable binary inputs and outputs
• Circuit breaker condition monitoring
• Trip circuit supervision
• Automatic self-supervision
• Synchronizm check function
• Menu-based HMI system
• Configurable LED indication
• Metering and recording functions
Phase Overvoltage Protection
GRD130 provides four independent phase overvoltage elements with programmable
dropoff/pickup(DO/PU) ratio. OV1 and OV2 are programmable for inverse time (IDMT) or
definite time (DT) operation. OV3 and OV4 have definite time characteristic only.
Figure 2.1.1 shows the characteristic of overvoltage elements.
Definite time reset
The definite time resetting characteristic is applied to the OV1 and OV2 elements when the
inverse time delay is used.
If definite time resetting is selected, and the delay period is set to instantaneous, then no
intentional delay is added. As soon as the energising voltage falls below the reset threshold, the
element returns to its reset condition.
If the delay period is set to some value in seconds, then an intentional delay is added to the reset
period. If the energising voltage exceeds the setting for a transient period without causing tripping,
then resetting is delayed for a user-definable period. When the energising voltage falls below the
reset threshold, the integral state (the point towards operation that it has travelled) of the timing
function (IDMT) is held for that period.
Phase Undervoltage Protection
GRD130 provides four independent phase undervoltage elements. UV1 and UV2 are
programmable for inverse time (IDMT) or definite time (DT) operation. UV3 and UV4 have
definite time characteristic only.
Definite time reset
The definite time resetting characteristic is applied to the UV1 and UV2 elements when the
inverse time delay is used.
If definite time resetting is selected, and the delay period is set to instantaneous, then no
intentional delay is added. As soon as the energising voltage rises above the reset threshold, the
element returns to its reset condition.
If the delay period is set to some value in seconds, then an intentional delay is added to the reset
period. If the energising voltage is below the undervoltage setting for a transient period without
causing tripping, then resetting is delayed for a user-definable period. When the energising
voltage rises above the reset threshold, the integral state (the point towards operation that it has
travelled) of the timing function (IDMT) is held for that period.
This does not apply following a trip operation, in which case resetting is always instantaneous.
Binary Output
All the binary outputs of the GRD130 except the relay failure signal are user-configurable. It is
possible to assign one signal or up to four ANDing or ORing signals to one output relay. Available
signals are listed in Appendix C.
It is also possible to attach Instantaneous or delayed or latched reset timing to these signals.
Appendix H shows the factory default settings.