Siemens SINAMICS PERFECT HARMONY GH180, Function Manual

Page: 270 / 538

This external protection must be supplied by the customer and is not within the scope of the
design.
Down Transfer of a PMM
With PMMs, down transfer is used to transfer a motor from the line to the drive. With NXGpro
control, the drive monitors the output voltage before locking-in to the motor frequency via the
spinning load algorithm. For the drive to perform this action, the drive contactor must be closed
at the beginning of the down transfer sequence while the drive output is still disabled. The drive
is capable of locking-in within a few milliseconds. The drive then raises the output torque current
before indicating that it is ready to accept the motor and open the line contactor.
The starting sequence for the PMM requires the drive to go through the high starting torque
mode. This must be bypassed if the motor is spinning, most importantly at the line frequency.
8.17.14 Parameters for Synchronous Transfer Operation (L29)
The Synchronous Transfer Menu (2700) is used exclusively for synchronous transfer
applications. Refer to Section Options for Drive Menu (2) of Chapter Parameter Assignment /
Addressing for parameters associated with this function.
8.17.15 Pre-charge using Dedicated I/O
8.17.15.1 Electric Shock Hazard
DANGER
Electric Shock Hazard
During pre-chargeelectric shock hazardDuring pre-charge, medium voltage is present on the
primary side of the input transformer and upstream device, even though the MV contactor is
not closed.Stay clear of the primary side of the input transformer to avoid death or serious
injury.
8.17.15.2 Limiting Function (applicable to all precharge types)
A limiting function that will prevent multiple, back-to-back precharge attempts has been added
and affects all precharge types. This function will prevent successive precharge attempts from
occurring any more frequently than once per minute or 5 per hour. This is part of the permissive
algorithm used in Type 5 & 6, the output of which sets the "DriveReadyToPrecharge_I" flag.
This is disabled by default and can be enabled by setting the "PrechargeLimitationEnable_O" SOP
flag to true. If more than one attempt is made within a minute, the message "Precharge: too
often - more than 1 per minute!" will be produced. More than 5 attempts within an hour will
Advanced Operating Functions
8.17 Synchronous Transfer
Control Manual
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Operating Manual, A5E50491925A