Siemens SENTRON 3WL Reference Manual page 10

3WL Air Circuit Breakers
3WL Air Circuit Breakers/Non-Automatic Air Circuit Breakers up to 6300 A (AC)
General data
Withdrawable short-circuit, grounding, and bridging
units
Portable positively-driven grounding and short-circuit devices
are used for the disconnected system sections to verify isolation
from the supply at the workplace.
Withdrawable grounding units allow simple and comfortable
grounding. They are simply inserted into the guide frames in
place of the corresponding withdrawable circuit breakers. This
ensures that these devices are always first connected with the
grounding electrode and then with the components to be groun-
ded.
The grounding terminals are fitted to the side of the switch enc-
losure and establish the connection when inserted into the guide
frame.
Short-time current of the kA 15 (500 ms)
grounding terminal
Rated operational voltage V
Standards
All withdrawable terminals are short-circuited and grounded on
delivery.
Qualified electricians can easily convert it to a withdrawable
bridging unit by following the enclosed instructions.
In addition, the withdrawable unit can be adapted to various ra-
ted currents of a size.
Withdrawable short-circuit and grounding unit
The withdrawable short-circuit and grounding unit consists of a
breaker enclosure with penetration blades which are connected
with the short-circuiting link.
Depending on the version, the short-circuiting links are arranged
at the top or bottom. The grounding and short-circuit connec-
tions are established when the device is inserted.
It must be ensured that the side to be short-circuited and groun-
ded is not live. For this reason it is recommended that the with-
drawable unit is only wound in when the door is closed.
Withdrawable bridging unit
The withdrawable bridging unit consists of a breaker enclosure
in which all disconnection components and the operating me-
chanism have been replaced with simple connections between
the upper and lower contacts.
Auxiliary releases
Up to two auxiliary releases can be installed at the same time.
The following are available:
1 shunt release
or 1 undervoltage release
or 2 shunt releases
or 1 shunt release
+ 1 undervoltage release
Signal switch for auxiliary releases
One signaling contact is used for each auxiliary release to deter-
mine the positions of the auxiliary releases.
Shunt releases
When the operational voltage is connected to the shunt release,
the circuit breaker is opened immediately. The shunt release is
available in the versions 5 % ON period for overexcitation and
100 % ON period for permanent excitation. This means that it is
also possible to block the circuit breaker against being jogged
into closing.
10 Siemens · 2009
1000 (690 for size I)
EN 61230
An energy storage device for shunt releases allows the circuit
breaker to be opened even if the control voltage is no longer
available.
Undervoltage releases
The undervoltage release causes the circuit breaker to be
opened if the operational voltage falls below a certain value or is
not applied. The circuit breaker cannot be closed manually or by
means of an electrical ON command if the undervoltage release
is not connected to the operational voltage. The undervoltage re-
lease has no delay as standard. A delay can be set by the cus-
tomer in the range between t
d
In addition, an undervoltage release with a delay in the range
from 0.2 to 3.2 s is available.
Closing solenoid
The closing solenoid is used to close the circuit breaker electri-
cally by means of a local electrical ON command or by a remote
unit.
Motorized operating mechanisms
The operating mechanism is used to load the storage spring au-
tomatically.
The operating mechanism is activated if the storage spring has
been unloaded and the control voltage is available.
It is switched off automatically after loading. This does not affect
manual operation of the storage spring.
Indicators, signals, and control elements
Motor shutdown switch
Control switch for switching off the motorized operating mecha-
nism (automatic loading).
Operating cycles counter
The motorized operating mechanism can be supplied with a 5-
digit operating cycles counter. The display is incremented by "1"
as soon as the storage spring is fully loaded.
Resetting the manual tripped signal
When the circuit breaker has tripped, this is indicated by the
protruding red mechanical tripped indicator on the ETU. When
the mechanical tripped indicator is activated, the tripping sole-
noid and tripped signal are reset. If this display is to be reset re-
motely, the reset button can be equipped with a reset solenoid.
This option allows the circuit breaker to be reset both manually
and electrically.
Automatic resetting of reclosing lockout
When the ETU is activated, reclosing of the circuit breaker is pre-
vented until the release is either electrically or manually reset. If
the "Automatic resetting of reclosing lockout" option is used, the
pre-tensioned circuit breaker is ready to close immediately after
tripping. Resetting the manual tripped indicator is not included
in this option.
Tripped signal switch
If the circuit breaker has tripped due to an overload, short-cir-
cuit, ground fault or extended protection function, the tripped si-
gnal switch can indicate this. This signal switch is available as
an option. If the circuit breaker is used for communication, this
option is supplied as standard.
Ready-to-close indicator switch
The SENTRON 3WL circuit breakers are equipped with an opti-
cal ready-to-close indicator as standard. In addition, the ready-
to-close status can be transmitted by means of a signal switch
as an option. If the switch is used for communication, the signal
switch is supplied as standard.
< 80 ms and t < 200 ms.
d