TAVRIDA ELECTRIC Rec15, Техническое руководство

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OC protection consists of six (6) individual overcurrent elements providing three stages of protection for both
the Forward () and Reverse (Source-) power flow directions: OC1+, OC1-, OC2+, OC2-, OC3+, OC3-
.
OC1
Phase overcurrent low set element OC1 is designated to provide time delayed trips. It is enabled in any
selected sequence in t
he Overcurrent Reclosing element. „I“ (Instantaneous) stands for accelerated and „D“
(Delayed) for delayed step of overcurrent protection in an autoreclosing sequence.
OC2
Phase overcurrent low set element OC2 is designated to provide accelerated trips. If a sequence step in the
Overcurrent Reclosing Element is set „D“ OC2 element is disabled. If a sequence step in the Overcurrent
Reclosing element is set „I“ OC2 element is enabled.
OC3
Phase fault high set instantaneous element provides protection against phase high current faults with a
reduced number of trips to lockout. If there is no intention to reduce the number of trips to lockout at high
current faults, enabling this element is not recommended. OC1 and OC2 allow reduction of tripping time to any
desired value at high currents.
For details on available TCC refer to Table 20 of this guide.
OC3 element settings are described in Table 21.
Earth Fault (EF)
This element is available
for OCR mode “Recloser” only.
This element provides protection against single phase and double phase earth faults.
EF protection consist of six (6) individual overcurrent protection elements providing three stages of protection
for both the Direct () and Reverse power flow (Source-) directions: EF1+, EF1-, EF2+, EF2-, EF3+,
EF3-.
EF1
Earth fault low set element EF1 is designated to provide time delayed trips. It is enabled in any selected
sequence in the Overcurrent Reclosing element. „I“ (Instantaneous) stands for accelerated and „D“ (Delayed)
for delayed step of overcurrent protection in an autoreclosing sequence.
EF2
Earth fault low set element EF2 is designated to provide accelerated trips. If a sequence step in the Overcurrent
Reclosing Element
is set „D“ EF2 element is disabled. If the sequence step in the Overcurrent Reclosing
element is set „I“ EF2 element is enabled.
EF3
Earth fault high set instantaneous element provides protection against high earth current faults with a reduced
number of trips to lockout. If there is no intention to reduce the number of trips to lockout at high current faults,
enabling this element is not recommended. EF1 and EF2 allow reduction of tripping time to any desired value
at high currents.
For details on available TCC refer to Table 17 of this guide.
EF3 element settings are described in Table 18.
Table 17
– TCC types
Settings Designation Range Default
Type of time current
characteristic
TCC
ANSI: Extremely Inverse (EI), Moderately Inverse (MI), Very Inverse (VI)
IEC: Extremely Inverse (EI), Very Inverse (VI), Inverse (I)
Definite Time (TD)
Custom: custom curves are available on request. Contact Tavrida
Electric representative.
TD