GE Gerapid 2607 User Manual page 5

3. Technical information
3.1 Introduction
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Gerapid is a high-speed DC circuit breaker. This is a sin-
gle-pole DC breaker, primarily designed f or use in railway
power distribution systems with operating currents up to
8000 A (Code 1) and operating v oltages up to 3600 V
(Code 2). Additional applications are special industrial
plants such as electrolysis, mining or steel mills.
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Gerapid breaker has a very high interruption capacity
combined with a c urrent limiting characteristic. The arc
chute works on the basis of an asbestos-free arc splitting
principle.
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A wide variety of accessories and spares are av ailable for
maintenance, repair, or as a possible enhancement. The
breaker is configured by using the catalogue coding
system, which is describe in section 7. 1. Eac h rating, op-
tion or accessory has a code number (i.e OCT – code 7).
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Closing of the circuit breaker is performed through a
high-power solenoid drive (Code 3).
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During inspections, opening and closing may be carried
out by means of a hand lever (C ode 16), whic h is mounted
onto the armature of the closing drive.
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Overload tripping and release is obtained directly by
means of the OCT release (C ode 7), or optionally by ED
impulse release (Code 12). Indirect remote tripping c an be
achieved by means of a shunt trip, or optionally by a zero
voltage release (Code 11).
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Gerapid breakers have a compact and enclosed con-
struction [Fig. 4]. Gerapid is IP 00 protected. All parts are
mounted on thick-walled, non-breakable and fireproof in-
sulation panels.
Fig. 4 M odular construction overview
2009-09-02 S47183e rev.03
3.2 Components and accessories
3.2.1 Contact system
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3.2.2 Arc chute (Code 2)
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Design and specifications are subject to change without notice
All Gerapid breakers are equipped with a two-stage con-
tact system [Fig. 5], 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.
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.
Arc runner
Arcing contact
Flexible band
Braid
Fig. 5 Two types of the contact system: after 11/2003 (upper)
and before 11/2003 (low er)
Compact and modular design of the arc system requires
no additional magnetic support and allows small safety
distances with high breaking capacity.
Because of the c ompact dimensions, these breakers c an
be installed in extremely small enclosures (from 500 mm;
1.65 ft) and offers a cost-effective solution for replace-
ments.
An adaptor [Fig. 43] is used to mount the v arious arc
chutes for different operating voltages on the breakers.
The arc chutes consist of a highly durable, arc-proof ma-
terial, in whic h 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 c athode
voltage drop. Because of their high heat capacity, the
plates and arc chute walls absorb a large amount of the
arc's energy.
Main contact
Main contact
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