ABB RED650 Applications Manual

reclosing of the line breakers. The dead time selected should be long enough to
ensure a high probability of arc de-ionization and successful reclosing.
For individual line breakers, auto reclosing equipment, the required circuit breaker
dead time is used to determine the “dead time” setting value. When simultaneous
tripping and reclosing at the two line ends occurs, line dead time is approximately
equal to the auto recloser “dead time”. If the auto reclosing dead time and line
“dead time” differ then, the line will be energized until the breakers at both ends
have opened.
Open
Closed
Operate time
Line
protection
Circuit
breaker
Break time
Trip command
Contacts separated
Arc extinguishers
Fault duration Circuit breaker open time
Fault duration
Resets
Instant of fault
Operates
Break timeClosing time
Operate time
Fault
Operates
Resets
Close command
Contact closed
Set AR dead time Reclaim time
Auto-reclosing
function
Start AR
Reclosing
command
AR reset
IEC04000146-3-en.vsd
IEC04000146 V3 EN-US
Figure 101: Single-shot automatic reclosing at a permanent fault
Single-phase tripping and single-phase automatic reclosing is a way of limiting the
effect of a single-phase line fault on power system operation. Especially at higher
voltage levels, the majority of faults are of single-phase type (around 90%). To
maintain system stability in power systems with limited meshing or parallel routing
single-phase auto reclosing is of particular value. During the single-phase dead
time the system is still capable of transmitting load on the two healthy phases and
the system is still synchronized. It requires that each circuit breaker pole can be
operated individually, which is usually the case for higher transmission voltages.
A somewhat longer dead time may be required for single-phase reclosing
compared to high-speed three-phase reclosing. This is due to the influence on the
fault arc from the voltage and the current in the non-faulted phases.
Section 12 1MRK 505 393-UEN B
Control
230 Line differential protection RED650 2.2 IEC
Application manual

ABB RED650 Specifications

General

Brand	ABB
Model	RED650
Category	Protection Device
Language	English