Siemens SINAMICS GM150, Operating And Installation Instructions

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3.5.5 Make-proof grounding switch
The make-proof grounding switch grounds the voltage DC link. This ensures that no hazardous
voltages are present in the DC link when the doors are opened.
To ensure that the drive functions safely, the actuating lever for the make-proof grounding
switch must be removed.
3.5.6 Circuit-breaker (provided by the customer)
To ensure adequate protection for converters, the circuit-breaker provided by the customer
must fulfill the following requirements:
● The maximum time between when the circuit-breaker trips to when a no-current state (I=0)
is reached is 80 ms.
● The circuit breaker must be equipped with an undervoltage tripping function.
● Avoid additional delay times when controlling the circuit breaker. All commands from the
converter to the circuit breaker must act directly without intervention of coupling relays.
● A feedback signal must be available for each of the circuit-breaker states CLOSED and
OPEN. The feedback signals must not be delayed. Consequently, do not use any coupling
relays.
● The circuit-breaker is controlled and released from the converter closed-loop control. If this
has not been enabled, under no circumstances should you switch on the circuit-breaker by
external mechanical or electrical means.
● To protect the converter transformer, ensure that overcurrent protection is in place.
3.5.7 Converter transformer
A three-winding transformer is required for the 12-pulse Basic Line Module. The secondary
windings of the three-winding transformer have a phase shift of 30°el, which results in a 12-
pulse supply with correspondingly lower line harmonics.
With a 24-pulse Basic Line Module, two three-winding transformers are required. The
additional shifting of the primary-side windings for the two transformers by +7.5° or –7.5° allows
a 24-pulse supply to be generated. Instead of the two three-winding transformers, a five-
winding transformer can be used (after consultation with the transformer manufacturer).
Consider the following properties during the configuration:
● Short-circuit voltage u
k
≥ 8% (in relation to 10 MVA)
● Transformer taps for voltage adjustments:
2 x 2.5% or +/- 5% if a sine-wave filter is used. The winding transformer taps are normally
located on the primary side of the transformer.
● The voltages and insulation for the secondary-side windings must be dimensioned as
shown in the following table:
Description
3.5 Description of the components
SINAMICS GM150 6SL3815-2LN41-4AA2
38
Operating Instructions 04/2017