Pre-Charge Using Dedicated I/O; Type 4 Pre-Charge (Resonant-Open Transfer-Capacitors Only) - Siemens SINAMICS PERFECT HARMONY GH180 Function Manual

produce the message "Precharge: too often - more than 5 per hour!" Both messages will appear
in the event log along with the "not ready" alarm message.
Should a precharge attempt be made when DriveReadyToPrecharge_I is false, an alarm "Not
ready to precharge" is set and displayed on the keypad. The alarm will be cleared when the
DriveReadyToPrecharge_I condition is valid again – but must be acknowledged as with other
alarms. Therefore, this flag should be used in the logic to create the precharge attempt. These
conditions define the alarm active: Alarm active when precharge enable is true, drive is not ready
to precharge, no precharge fault active, and drive not actively in precharge.
This flag will not be set true if the drive has experienced precharge once in the past minute, or
5 times in the past hour. If an attempt is made to precharge with the DriveReadyToPrecharge not
set to true, then a message stating the drive is not ready will be displayed on the keypad and
recorded in the event log. The precharge start MUST be removed before attempting again, and
DriveReadyToPrecharge must return to true. Then the drive can respond to precharge.
8.17.15.3

Pre-charge using Dedicated I/O

The software in these pre-charge types use dedicated I/O for controlling all contactors. Type 5
and 6 pre-charge read inputs and control outputs directly with no intervention from the SOP. The
only exception is the StartCellPrecharge_O flag to start pre-charge once the drive is ready
to pre-charge (DriveReadyToPrecharge_I is true).
Note
Water-cooled 750 V AP type cells must use type 5 open or type 6 closed pre-charge.
Other drive types may use type 5 open or type 6 closed pre-charge if hardware is in place.
Note
Air-cooled drives used for floating platforms may use type 6 (closed) pre-charge only. Pre-charge
for these cell types is for limiting transformer in-rush only; and, this is achieved through type 6
(closed) pre-charge.
See also
Type 5 (Open) Pre-charge (Page 276)
Type 5 (Open) Pre-charge (Page 276)
Type 6 (Closed) Pre-charge (Page 281)
Preconditions for Pre-charge Types 5 and 6 (Page 273)
8.17.15.4

Type 4 Pre-charge (resonant-open transfer-capacitors only)

Type 4 Pre-charge is open pre-charge mode for use with a drive within the 6SR4 family. The
introduction of the cell for this air-cooled drive brought the requirement to precharge the
capacitors with no pre-magnetization for the transformer.
Precharge was added to the new drive, with an open transference of power from the precharge
source to the line. The main purpose was to limit inrush current by limiting the charging current
NXGPro+ Control Manual
Operating Manual, A5E50491925A
Advanced Operating Functions
8.17 Synchronous Transfer
269