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3VT3 Molded Case Circuit Breakers up to 630 A
Accessories and Components
Motorized operating mechanisms
4/32
Siemens LV 36 · 2008
4
■
Design
The motorized operating mechanism is part of circuit breaker
accessories enabling you to switch the circuit breaker on and off
remotely. Modular conception of the motor mechanism enables
simple mounting on the circuit breaker (also additionally) after
the circuit breaker accessory compartment cover is removed.
The fixed motor can be sealed. 3VT3 circuit breakers with motor
mechanism can be used in the most demanding industrial appli-
cations such as protection of standby sources, synchronization
of two sources, etc. and anywhere it is necessary to ensure au-
tomated and unmanned operation of electrical equipment.
The motor mechanism are equipped with spring storage units
and due to accumulated energy to trip the circuit breaker, it is no
problem to trip the circuit breakers within times up to 60 ms.
Releasing of the storage unit and tripping of the circuit breaker
is ensured by a closing coil that belongs to standard equipment
of every motor mechanism. The time before the circuit breaker is
tripped using the motor mechanism is 900 ms. This method of
tripping is suitable for controlling technological entities. When
faster circuit breaker tripping is required (e.g. emergency STOP
button), it is possible to use the motor mechanism in combina-
tion with undervoltage release or shunt trip.
• On the motor mechanism front panel there is a selector switch
to select the drive modes with a possibility to indicate remotely
the selector switch state. The first mode is automatic remote
control (selector switch in position AUTO). This is the standard
position in automatic operation. The second mode is manual
control (selector switch position MANUAL), the motor mecha-
nism does not need any voltage to perform its function.
• Remote switching on and off in position AUTO is carried out
using push buttons that must be connected to the drive unit
connector, furthermore, this position makes it is possible to
control the circuit breaker with the push buttons on the drive
unit front panel.
• In MANUAL mode it is possible to switch on and off using the
green and red push buttons on the front panel of the motor
mechanism cover. The function of the remote control ON but-
ton in MANUAL mode is locked up, whereas the function of the
remote control OFF button remains active for safety reasons.
• The motor mechanism, apart from the circuit breaker, recog-
nizes only two fixed positions. In the first position the circuit
breaker is ON. When the circuit breaker is tripped in AUTO
mode by overcurrent releases or auxiliary trips, then because
of mechanical link between the circuit breaker and the motor
mechanism, a pulse will be generated to wind up the spring of
the storage unit automatically. The motor mechanism can be
wound up automatically, depending on operator’s demand, by
permanent closing of switch S or after the circuit breaker is
checked by switching S switch on. In the second fixed posi-
tion the circuit breaker is switched off and the loaded drive is
ready to switch the breaker on after it has received the setting
pulse.
• The motor mechanism makes it possible to control the circuit
breaker after the loss of control voltage. In MANUAL and
AUTO modes, it is possible to wind up the storage unit by re-
peated rotation of the foldable handle. After the storage unit is
wound up, it is possible to switch the circuit breaker on and off
using the control buttons on the front panel of the motor mech-
anism.
• On the front panel there is a storage unit status indicator indi-
cating locally what state the 3VT3 motor mechanism unit stor-
age is in and whether it is possible to switch the circuit breaker
on. 3VT3 motor mechanism enable to obtain a storage status
signal from the terminal strip also remotely. 3VT2 motor mech-
anism have optional designs, alternatively with MAN-
UAL/AUTO indication.
• The mechanism can be furnished with an electromechanical
operations counter that may be installed in the drive cover or
fixed beyond the circuit breaker space (e.g. in the switchgear
door) or in the switchgear space using a metal holder in-
cluded in the supply of external operations counter and its
connecting can be done using connectors.
• The mechanism can be locked in off position using as many
as three padlocks with shank diameter max. 4.3 mm.
• An 3VT9 300-3MF20 cover can be affixed to the drive’s turn-
on switch and then sealed. The cover prevents turning on the
circuit breaker from the drive panel.
• Extension cable 3VT9 300-3MF00 has a connector on one
side that connects to the connector on the motor mechanism
and conductors on the other side that connect, for example, to
a terminal block.
1)
For sequence of control pulses, see page 4/33.
Order No.
3VT9 300-1S.00
Operational voltage U
e
V AC 24 ,48, 110, 230
DC 24, 48, 110, 220
Rated frequency f
n
Hz 50/60
Control pulse length for storing
400 ms
∞
1)
Control pulse length
for switching on
20 ms ... 700 ms
1)
for switching off
400 ms ...
∞
1)
Time before switching on
ms < 60
Time before switching off
ms 900
Frequency of cycles ON/OFF
3 contact making/hr
Frequency of cycles - instant
successive ON/OFF cycles
10 contact making
Mechanical endurance
20000 contact making
Input power
AC 100 VA, DC 100 W
Protection
• AC 24, 48, 110 V; AC 230 V
LSN 4C/1; LSN 2C/1
• DC 24, 48, 110 V; DC 220 V
LSN-DC 4C/1; LSN-DC 2C/1
Rated operating current
AUTO / MANUAL switches
I
e
/U
e
V AC 5 A/250
DC 0.5 A/250
Order No.
3VT9 300-3MF00
Number of conductors
12
Conductor cross sections S mm
2
0.35
Conductor lengths
cm 60