Siemens SINAMICS G130 Engineering Manual page 27

At higher supply voltage of V
taken into consideration.
At lower supply voltage of 0.9 • V
proportion to the supply voltage. If a power reduction cannot be tolerated, converter and motor must have current
reserves, in order to compsenate for the lower supply voltage with an increased current input. This may make the
over-dimensioning of the drive necessary.
Short-term permissible supply voltage variations (< 1 min)
Short-term operation (i.e. up to 1 min) of SINAMICS units is permissible within the following range of the nominal
supply voltage:
In this range all the auxiliaries supplied with 230 V by the internal transformer still operate within their permissible
limits, but the fans also supplied with 230 V by an internal transformer can no longer, within the range of permissible
frequency tolerances, fully provide the cooling air flow required by the power components. As a result of this reduced
cooling capacity, operation must be limited to a time period of < 1 min. The DC link voltage still has a wide safety
margin to the under and over-voltage trip level regardless of whether a regulated rectifier (Active Infeed) or
unregulated rectifier (Basic Infeed or Smart Infeed) is used.
In this short-term, permissible supply voltage range, it must also be taken into consideration that the drive power
decreases in proportion to the supply voltage. If a power reduction cannot be tolerated, the converter and motor must
have current reserves in order to compensate for the reduced supply voltage with a higher current input. This may
mean that the drive has to be over-dimensioned.
Permissible supply voltage dips
On the following pages, dips which do not cause fault tripping of the drive will be termed permissible supply voltage
dips. So that no fault trip occurs, two conditions must be fulfilled:
•
All auxiliaries in the converter, which are supplied with 230 V – with the exception of the fans – and also the
electronics supplied with 24 V DC, must remain in operation,
and
•
The DC link voltage must not reach the under-voltage trip level.
Whether these conditions can be fulfilled during supply voltage dips depends on a lot of factors. These factors are:
•
The supply of auxiliaries with 230 V and the supply of the electronics with 24 V DC (directly from the power
supply, via the internal transformer or from a secure, external supply e.g. an uninterruptible power supply)
•
The type of the SINAMICS lnfeed (regulated or unregulated)
•
The load condition of the drive (full load, partial load or no-load)
•
The depth of the supply voltage dip
•
The duration of the supply voltage dip
The supply for the auxiliaries with 230 V AC and for the electronics with 24 V DC is produced in the cabinet
units SINAMICS G150, S120 Cabinet Modules and S150 as a standard via built-in transformers internal to the units,
which are supplied directly by the power supply voltage. Consequently, the supply voltage dips have an effect directly
on the auxiliaries supplied with 230 V. If the supply voltage dips too much and over a too long time period, the
auxiliaries (including the internal switch-mode power supply for the 24 V supply for the electronics) will fail. This leads
to a fault trip.
If the voltage of the auxiliaries (230 V) and the electronics (24 V) should remain in operation even during large and
long supply voltage dips, the voltage of 230 V must be supplied from a secure, external supply, such as an
uninterruptible power supply (UPS). For that two jumpers must be removed inside the cabinet unit and the external
230 V supply must be connected as shown in the following diagram with the example of a G150 cabinet unit. Also the
voltage of 24 V can be supplied from a secure, external supply by disconnecting the internal switch-mode power
supply and replacing it by a secure, external supply.
Fundamental Principles and System Description
≤ V ≤ 1.1 • V
no restrictions in the operational behaviour of the drive need to be
N Line N
≤ V ≤ V
it must be taken into consideration that the drive power decreases in
N Line N
≤ V
0.85 • V
N
Engineering Information
≤ 0.9 • V
Line N
SINAMICS Engineering Manual - May 2008
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