Functions
2.2 Automatic reclosure function (optional)
SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009
43
2.2
Automatic reclosure function (optional)
Experience shows that about 85% of the arc faults on overhead lines are extinguished automatically after being
tripped by the protection. The line can therefore be re-energised. Reclosure is performed by an automatic
reclose function (AR).
Automatic reclosure is only permitted on overhead lines because the option of automatic extinguishing of a fault
arc only exists there. It should not be used in any other case. If the protected object consists of a mixture of
overhead lines and other equipment (e.g. overhead line directly connected to a transformer or overhead
line/cable), it must be ensured that reclosure can only be performed in the event of a fault on the overhead line.
If the circuit breaker poles can be operated individually, a single-pole automatic reclosure is usually initiated in
the case of single-phase faults and a three-pole automatic reclosure in the case of multi-phase faults in the
network with earthed system star point. If the fault still exists after reclosure (arc not extinguished or metallic
short-circuit), the protection issues a final trip. In some systems several reclosing attempts are performed.
7VK61 allows reclosure after three-pole, single-pole and single-pole /three-pole tripping. It is possible to
execute several reclosing attempts.
Single-pole or single-pole/ three-pole auto-reclosure requires the fault protection function of the feeder to issue
phase-segregated trip commands.
Signals between the feeder protection and 7VK61 are exchanged via the binary inputs and outputs of the relay.
7VK61 may also be controlled by several protective installations (e.g. main and backup protection). In this case
7VK61 is capable of tripping both protective installations in all three poles if only one device trips multi-pole or
if both protective installations attempt to trip single-pole in different phases.
Using two 7VK61 with two feeder protection installations is also possible (see margin heading „2 Protection
Relays with 2 Automatic Reclosure Circuits“).
2.2.1
Function Description
Reclosure is performed by an automatic reclosure circuit (ARC). An example of the normal time sequence of
a double reclosure is shown in the figure below.
Figure 2-4
Timing diagram of a double-shot reclosure with action time (2nd reclosure successful)
Summary of Contents for Siprotec 7VK61
Page 8: ...Preface SIPROTEC 7VK61 Manual C53000 G1176 C159 3 Release date 05 2009 8 ...
Page 14: ...Contents SIPROTEC 7VK61 Manual C53000 G1176 C159 3 Release date 05 2009 14 ...
Page 316: ...Literature SIPROTEC 7VK61 Manual C53000 G1176 C159 3 Release date 05 2009 316 ...
Page 328: ...Glossary SIPROTEC 7VK61 Manual C53000 G1176 C159 3 Release date 05 2009 328 ...
