Set the reclosing time of phase fault (negative phase sequence included), ground fault and SEF fault. The reclosing time is applied individually according to the fault type.
1) Intervals Setup – PHASE/NEQ SEQ’
PRIMARY, ALTERNATE or EITBANK SETTING / INTERVALS / … / Reclose 1
Range Applicable for lower than Ver 3.4 of ETR300-R : 0.5 ~ 600.0 sec Applicable for Ver 3.4 or higher of ETR300-R : 0.1 ~ 600.0 sec Default 0.6 Step 0.1 sec
This setting is used to change the first reclose interval time between the first trip operation and the close operation.
PRIMARY, ALTERNATE or EITBANK SETTING / INTERVALS / … / Reclose 2 Range 1 ~ 1800 sec
Default 2 Step 1 sec
This setting is used to change the first reclose interval time between the first trip operation and the close operation.
PRIMARY, ALTERNATE or EITBANK SETTING / INTERVALS / … / Reclose 3 Range 1 ~ 1800 sec
Default 2 Step 1 sec
This setting is used to change the first reclose interval time between the first trip operation and the close operation.
[PHASE/NEG SEQ’]
>Fast Curve-NEQ: 2 [0~5:1]
PRIMARY, ALTERNATE or EITBANK SETTING / INTERVALS / … / Reclose 4 Range 1 ~ 1800 sec
Default 15 Step 1 sec
This setting is used to change the first reclose interval time between the first trip operation and the close operation.
2) Intervals Setup – GROUND
The ground interval settings process is the same as the phase interval.
3) Intervals Setup – SEF
The SEF interval settings process is the same as the phase interval.
4) Intervals Setup – OTHER
PRIMARY, ALTERNATE or EITBANK SETTING / INTERVALS / OTHERS/ Reset T(AR) Range 3 ~ 180 sec
Default 30 Step 1 sec
It is to select Reset time during auto reclosing.
During reclosing sequence operation, if current is back to normal for this set time, recloser sequence is Reset. Generally, Reclosing reset time shall be set longer than present reclose sequence time. During reclose sequence time, if a fault current is removed, ‘Reset T(AR)’ time starts and during
‘Reset T(AR)’ time, a fault is detected again, Reset timer is reset.
PRIMARY, ALTERNATE or EITBANK SETTING / INTERVALS / OTHERS/ Reset T(LO) Range 1.00 ~ 600.00 sec
Default 10.00 Step 0.01 sec To set Lockout reset time.
After recloser is closed by locally or remotely, within this set time, auto reclosing is not activated. It is to eliminate reclosing sequence if a fault current is detected after manual closing, and to have waiting time for feeder stabilization. After this set time, Recloser function is activated.
[OTHERS]
Reset T(AR): 30
>Reset T(LO): 10.00 [1.00~600.00:0.01s]
[OTHERS]
>Reset T(AR): 30 Reset T(LO): 10.00 [3~180:1s]
[PHASE/NEG SEQ’]
Reclose 3: 2
>Reclose 4: 15 [1~1800:1s]
PRIMARY, ALTERNATE or EITBANK SETTING / INTERVALS / OTHERS/ C/P Wait Range 1.00 ~ 600.00 sec
Default 60.00 Step 0.01 sec Close Power Wait. : Waiting time to get power supply.
During reclose sequence, power supply is not enough to operate mechanism, it counts for this set time and if the power supply is not provided, then reclose sequence is stopped and lockout.
7.1.1.1. Lockout
The lockout state occurs under any of the following conditions :
y When RECLOSE ENABLED LED is OFF and a fault current is occurred.
y When the high current lockout has occurred.
y After manual closing, a fault current is occurred within Reset T(LO).
y When recloser is manually opened.
y After TRIP occurs, the fault current is not removed or the recloser’s 52a contacts do not change status of the recloser opened.
y After manual closing, Close Power Waiting time is over.
The Lockout State is cleared when the recloser has been manually closed by local/remote control and the reset time has expired.
“Figure 7-3. Protection sequence containing 2F3D operations followed by lockout” shows 2F3D(2 Fast and three Delay) operation and lockout result. The total number of operation is set for 5times and Fast curve operation is set for 2 times. (3 times operation works with Delay Curve)
[OTHERS]
Reset T(LO): 10.0
>C/P Wait: 60.00 [1.00~600.00:0.01s]
(1) 1st Trip - 1st TCC(Fast) (2) 1st Reclose Interval Time (3) 2nd Trip - 2nd TCC(Fast) (4) 2nd Reclose Interval Time (5) 3rd Trip - 3rd TCC(Delay) (6) 3rd Reclose Interval Time (7) 4th Trip - 4th TCC(Delay) (8) 4th Reclose Interval Time (9) 5th Trip - 5th TCC(Delay)
Figure 7-3. Protection sequence containing 2F3D operations followed by lockout
7.1.1.2. Reset
If the faulted current is cleared before the lockout condition, the reclosing sequence automatically reset after passing the reset time interval.
If the fault condition occurs again during the reset time, the recloser will operate lockout after the completion of the remaining sequence.
“Figure 7-4. Reset Sequence operation after the 3rd reclosing as the fault current is cleared”
shows that, after 3rd reclosing operation, the fault current is disappeared.
(1) 1st Trip - 1st TCC (2) 1st Reclose Interval Time (3) 2nd Trip - 2nd TCC (4) 2nd Reclose Interval Time (5) 3rd Trip - 3rd TCC (6) 3rd Reclose Interval Time
Figure 7-4. Reset Sequence operation after the 3rd reclosing as the fault current is cleared
7.1.2. Phase (Fast/Delay) Time Overcurrents (51P)
The ETR300-R has two phase time overcurrent elements. The phase time overcurrent element contained in the ETR300-R, is set based on CT secondary current as connected to the current inputs.
The phase time overcurrent element is the most commonly used as a protective element for distribution systems and also used in both down-line and back-up recloser protection. The phase time overcurrent element provides a time delay versus current for tripping that is used for an inverse time curve characteristic coordinated with current pickup value, curve type, time dial, time adder, minimum response time setting and reset type. This inverse characteristic means that time overcurrent element operates slowly on small values of current above the pickup value and operates faster when current increases significantly above the pickup value. The phase time overcurrent element is enabled in the Primary, Alternate settings and PROTECTION ENABLED in user interface panel.
Multiple time curves and time dials are available for the phase time overcurrent element to respectively coordinate with other protection elements in the ETR300-R and other external devices on the distribution system. ANSI, IEC, ESB, USER and non-standard time current curves are included in the ETR300-R.
A User Programmable curve option is also available for user to allow creating custom’s time current curves for more enhanced coordination than the standard curve types.
The Reset type can be either instantaneous or linear. The phase time delay reset mode applies to the ANSI, IEC, ESB, USER curves. The instantaneous mode is used to coordinate with other instantaneous reset devices such as a recloser or other protective equipment on the distribution system. In the instantaneous mode, the time overcurrent element will reset instantaneously when the measured current level drops below the pickup setting for one cycle. Linear reset mode, the recloser is used for the cooperation with the protection device necessary for delay time as mechanical relay reset.
If the recloser is closed by pressing the CLOSE button on the front panel, or by an remote control or via SCADA, the phase time overcurrent element is prevented from tripping for a period specified by the Cold load pickup scheme.
The following setting is used to program the phase fast time overcurrent element.