Option L34 (Circuit Breaker On The Output Side) - Siemens SINAMICS G130 Engineering Manual

SINAMICS S120 Cabinet Modules
Engineering Information
Withdrawable version of circuit breaker

Option L34 (Circuit breaker on the output side)

Option L34 is a circuit breaker on the output side of the Motor Module and is designed for the purpose of
disconnecting the Motor Module from the motor terminals. The disconnection can thus carried out at full load.
Option L34 is required in the following applications with permanently-excited three-phase synchronous machines:
•
Drives with a high moment of inertia, which require a long time for comming to standstill and which generate
a voltage at the motor terminals during this time
•
Mechanically-coupled auxiliary drives, which can be mechanically driven by the main drive
•
Maintenance and repair at the converter, when the machine cannot, for example, be brought to a standstill
by means of mechanical braking.
•
Operation in the field weakening range in combination with a suitable limitation of the DC link voltage in the
converter (e.g. a Braking Unit) which, in the event of a fault tripping of the inverter, effectively limits
the DC link voltage until the circuit breaker is opened. For more detailed information, refer to the section
"Drives with permanent-magnet three-phase synchronous motors" of the chapter "Drive Dimensioning".
A rotating, permanently magnetized synchronous machine produces a voltage at its terminals which is in proportion
to the speed. The motor voltage is therefore present at the output terminals of the Motor Module as well as at the DC
link and the components connected to it. For disconnection in the event of a fault or for maintenance work, the circuit
breaker at the output is available as an option for S120 Cabinet Modules consisting of Motor Modules in chassis
format.
Option L34 consists of a circuit breaker which is located in a separate, 600 mm-wide cabinet to the right of the Motor
Module. It is controlled by the Motor Module via a terminal module, which, like the circuit breaker, is completely wired
inside the Cabinet Module. Pre-defined BICO logic circuits based on the free function blocks support the
commissioning process.
Circuit breakers are subject to limited load duty cycles. To increase their lifetime, they are not opened when the
inverter receives an „OFF" command (OFF1, OFF2, OFF3). Normally, the opening of the circuit breaker is initiated
when the Motor Module trips or the auxiliary supply of option L34 fails or the "OFF" button on the circuit breaker is
pressed. When the "OFF" button directly on the circuit breaker is pressed, the Motor Module will also be deactivated
by disabling the pulses.
SINAMICS Engineering Manual – May 2008
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© Siemens AG
In addition to the standard functions/ options, the
withdrawable version of the SENTRON WL circuit
breaker features the
functions:
• Position indicator on the breaker front panel
• Captive crank handle for moving the withdrawable
breaker
• Slide-in frame with guide rails for easier breaker
handling
• Locking capability to prevent movement of breaker
• Withdrawable breaker cannot be moved when the
breaker is closed
• Rated current coding between slide-in frame and
withdrawable breaker to prevent insertion of
incorrect breaker rating.
following supplementary