S47183-e   01/2008  Design and specifications are subject to change without notice  52 
 
7.3 Glossary 
- A - 
a-release – see Shunt trip device; 
Activating magnet – see Closing drive; 
Anti-pumping device – see SU control unit; 
Arc runners  – (also: arc probes; arc horns). Provide safe arc 
leading into the arc chute. There are two arc runners mounted 
in Gerapid breaker, front and back. 
Arcing contact – see pre-arcing contact; 
Auxiliary switch – (also: auxiliary contact; make/break contact; 
a-/b-contact). Switch containing up to 10 auxiliary contacts, me-
chanically operated by the mechanism of the breaker in case of 
switching operation. Auxiliary switch block is mounted in lower 
compartment of the control box. Every contact h can be NO or 
NC configured by appropriate wiring. 
-C- 
Closing drive – (also: activating magnet; closing solenoid; sole-
noid drive). Big black solenoid coil, mounted at the front of the 
breaker below the control box. It is used for electrically, re-
motely closing of the main contacts. Power consumption is up 
to 2.6kW. Closing time is ~150ms. 
Closing operation – (also: switching ON; CLOSE operation). It is 
operation, by which the breaker is brought from the OPEN posi-
tion to the CLOSED position. This is realizing by means of closing 
drive or hand lever. 
Closing solenoid - see Closing drive; 
Control terminals – (also: control sockets/plugs). Fully insulated 
sockets at the front cover of control box. Intended to use for 
connection the auxiliary control circuits. 
-E- 
ED coil – (also: electr-dynamic coil). An impulse coil, actuating 
element of ED tripping device, mounted on the base, under the 
movable arm. 
Electro-dynamic tripping device – (also: ED tripping; impulse re-
lease). Release device, consist of actuator (ED coil) and control 
circuit (NEKO PCB with C-bank). This is an optional auxiliary re-
lease, activated by high-energy impulse of current. The impulse 
is shaped by internal (NEKO) or external C-bank. Opening time is 
less 3ms. Time to charge capacitors is ~15sec. 
-F- 
Forced tripping release – (also: FTU; forced tripping device/unit). 
Fully insulated, direct tripping device, mounted under the bot-
tom of the breaker’s mechanism, in the way that small pin ex-
trudes. By pushing of this pin to the top, breaker will be tripped 
and open. 
-H- 
Hand lever – (also: manual control lever). Metal bar designed for 
direct, manual operating of solenoid closing coil. Hand lever can 
be used for both, closing and opening operation. It is intend to 
use only during maintenance. 
-M- 
Main circuit – (also: mains; primary circuit; current path). All the 
conductive parts of the breaker included in the circuit, which is 
intend to close or open. It consists of: main terminals (upper and 
lower),fix contact, flexible band and lower bus bar. 
Main terminals – (also: clusters;, main connections). These are 
two conductive bars provided for electrical connection to exter-
nal main circuit. Different configurations are offered. 
Manual control – (also: manual operating). Close or open opera-
tion by human intervention with using of hand lever. 
-N- 
NEKO control PCB – (also: ED coil control unit; internal C-bank 
control). Control circuit, designed as a single PCB, to supervise 
the operating of electrodynamic coil. It consists of control circuit 
and bank of capacitors, required to energize the ED coil. Control 
circuit is supervising ED coil operations. 
-O- 
OCT – see Over-Current Tripping unit; 
Opening operation – (also: switching OFF; OPEN operation). It’s 
an operation by which the breaker is brought from the CLOSED 
position to the OPEN position. This is realized by means of auxil-
iary tripping devices, OCT or hand lever. 
Over-Current Tripping unit – (also: OCT). It’s an instantaneous 
and direct mechanical release, tripping the breaker in case of 
overloads and short circuits. It is adjustable within predeter-
mined range. Opening time depends of short circuit conditions 
and shall not exceed 5ms. It does not need any imported en-
ergy, and is activated be means of magnetic energy from main 
circuit. 
-P- 
Position indicator – (also: position indicating device). Small de-
vice mounted at the front of closing drive, which indicates 
whether the breaker is in the open or close position. CLOSED 
position is marked as “I”. OPEN position is marked as “O”. It is 
fully mechanical device. 
Pre-arcing contact – (also: pre-contact; arcing contact). Arc con-
tact on which the arc is intended to be established, to avoid of 
wearing and burning of main contacts. It is mounted at the top 
of flexible band. It is easy to replace and is self compensating 
the contact force. 
-R- 
r-release – see Zero voltage release; 
-S- 
SEL – current measurement system, consist of sensing element 
and control circuit. The sensor is an insulated tube, mounted on 
the top terminal of the breaker. It’s using two Hall’s probes for 
sensing the current and its direction. The proportional voltage 
signal is transmitted to control circuit, placed in control box. The 
SEL control PCB is an opto-isolated transducer, which generates 
the standard output signals proportional to measured current. 
SEL control PCB - control circuit, designed as a single PCB, for 
controlling and transforming the current measurement signal 
from SEL sensor. 
Shunt trip device – (also: shunt release; a-release). Instantane-
ous release energized by means of voltage source. It’s directly 
tripping breaker’s mechanism within 50ms. It is used for remote 
OPEN operation and needs 24Vdc supply. There are available 
also versions for higher control voltages, supply directly and ex-
ternally. It is installed at the bottom of mechanic block. It is con-
trol by ST PCB and releasing by external “potential free” contact. 
Solenoid coil - see Closing drive; 
ST control PCB – control circuit, designed as a single PCB, to su-
pervise the operating of shunt trip release. 
SU control PCB – control circuit, designed as a single PCB, to 
supervise the remote closing operation by means of solenoid 
closing drive. It is obligatory installed in every breaker, and 
placed in control box. This control circuit provides also anti-
pumping function and self cut off function, to avoid electronics 
overheating during continues closing command. 
Switching ON – see Closing operation; 
Switching OFF – see Opening operation; 
-T- 
Trip-free mechanical switching device - mechanical switching 
device, the moving contacts of which return to and remain in 
the open position when the opening (i.e. tripping) operation is 
initiated after the initiation of the closing operation, even if the 
closing command is maintained. To ensure proper breaking of 
the current, which may have been established, it may be neces-
sary that the contacts momentarily reach the closed position. 
-U- 
UVR control PCB - control circuit, designed as a single PCB, for 
supervising the zero-voltage release release. 
-Z- 
Zero-voltage release  – (also:  under-voltage; UVR; r-release). 
Tripping device, which permits a mechanical switching breaker 
to open, when the voltage across the terminals of the UVR falls 
below 3VDC. Opening time is less 50ms. It is used for remote 
OPEN operation or control voltage supervision. It is installed at 
the bottom of mechanic block, alternatively to ST device, and is 
control by UVR PCB. Can be and released by external, “potential 
free”, NO or NC contact.