GE Industrial Solutions GERAPID 8007R, 10007R WITH ARC CHUTES 1X2, 1X3 - Manual (Page 6)

3. Technical information
3.1 Introduction
• Gerapid R-type (rectifier type) is a single pole, high-speed
DC circuit breaker, designed for use in railway propulsion
power distribution systems with operating currents up to
8000 A (Code 1) and operating voltages up to 1200 V
(Code 2).
• Gerapid breaker has a very high interruption capacity
combined with a current limiting characteristic. The arc
chute works on the basis of an asbestos-free arc splitting
principle.
• A wide variety of accessories and spares are available for
maintenance, repair, or as a possible enhancement.
• Use the catalogue coding system described in section 7.1
to configure the breaker. Each rating, option or accessory
has own code.
• Closing of the circuit breaker is performed through a high-
power solenoid drive (Code 3).
• During inspections, opening and closing may be carried
out by means of a hand lever (Code 16), which is mounted
onto the armature of the closing drive.
• Tripping and release is obtained directly by means of the
POCT release (Code 7), or optionally by ED impulse release
(Code 12). Indirect remote tripping can be achieved by
means of a shunt trip, or optionally by a zero voltage
release (Code 11).
• Gerapid breakers have a compact and enclosed
construction. Gerapid is IP 00 protected. All parts are
mounted on thick-walled, non-breakable and fireproof
insulation panels.
3.2 Components and accessories
3.2.1 Contact system
• Gerapid breakers are equipped with a two-stage contact
system [Fig. 3], consisting of a main contact and an
arcing contact. With this proven design, the main contact
is not subjected to any appreciable wear or tear. Each
breaker has two such contacts, working as a single pole.
• The main contact is made of a silver composite material.
The arcing contact and link braid are made of copper and
can be easily replaced.
• The flexible bend is linked to the arcing contact by means
of very tight braid.
Fig. 3 Two-stage contact system
3.2.2 Arc chute (Code 2)
•
Compact and modular design of the arc system requires
no additional magnetic blow out support and allows small
safety distances with high breaking capacity.
• An adaptor [Fig. 1] is used to mount the arc chute on the
breaker.
• The arc chutes consist of a highly durable, arc-proof
material, in which the arc plates have been integrated.
• The arc plates split the arc into partial arcs and increase
the arcing voltage by multiplying the anode and cathode
voltage drop. Because of their high heat capacity, the
plates and arc chute walls absorb a large amount of the
arc’s energy.
3.2.3 Mechanism
• Gerapid is equipped with a modular designed mechanism,
which is wear-resistant and nearly maintenance-free.
This mechanism ensures an extended electrical and
mechanical endurance of the breaker as well as a high
level of safety under all operation conditions.
• The breaker is rated for 10 000 operations when opened
by the shunt trip or zero voltage release, and 500
operations by means of ED impulse coil or POCT releases,
before maintenance should be required.
• The mechanism is mechanically latched in the CLOSED
position. The principle of a mechanically latched
mechanism offers an advantage compared to often used
electro magnet holding system. No auxiliary control
power source is required to keep breaker closed.
• The mechanism is provided with two tripping latches
[Fig. 4]. First latch, called “slow latch”, is used for opening
under normal conditions, like actuation of shunt trip or
zero-voltage release. The second one, “quick latch”, de-
clutches the main contact arm from the mechanism and
opens the contacts with an extremely short delay. This is
used when interrupting short-circuit or overloads. All
safety releases operate onto “quick latch” latch.
• The mechanisms in rectifier breakers are the same type,
but different from standard, feeder breakers mechanisms.
Therefore mechanisms cannot be exchanged between
rectifier and feeder breakers.
Fig. 4 Latching and tripping system
6 Design and specifications are subject to change without notice DTR01807 rev.02 2010-02-16