Basic Documentation

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Siemens VAV Compact Controller Modbus RTU A6V10631862_en--_e
Smart Infrastructure 2021-10-26
9.3 Parameter and function description
9.3.1 Vnom (nominal volume flow) [m3/h or l/s]
VAV boxes are ordered through an OEM according to the required nominal volume
flow (Vnom) and min. / max. volume flow settings (Vmin / Vmax). The maximum
volume flow for ventilating a room / zone can’t be higher than the nominal volume
flow.
9.3.2 Vmin / Vmax (minimum / maximum volume flow) [%]
These values limit the nominal volume flow by multiplying with Vnom. Their effect is
described in chapter 5.
9.3.3 Elevation above sea level [m]
This value enhances the accuracy of the differential pressure sensor to
compensate for the air density decreasing with increasing altitude. It can be set in
500m steps, so for a given building the setting closest to the actual altitude is to be
used.
Example: Altitude of building: 420m a.s.l. → use setting “500m”
9.3.4 Override control
The actuator can be operated in override control for checking / maintenance
purposes or system-wide functions (e.g. night-cooling).
9.3.4.1 Local override
The actuator enters this state when a service tool is connected by the service
interface (PPS2). Available commands:
• Open / Close (depends on opening direction)
• Min / Max (depends on Min/Max settings)
• Stop
If the actuator is in backup mode, it will be controllable in local override but resume
the backup mode
• when the service tool is disconnected,
• when the local override timeout is exceeded, or
• when the override control is set to “off”.
Timeout is 10s after the last read or write access.
9.3.4.2 Remote override
The actuator enters this state when an override command is sent over the bus. The
override control is available as Modbus register with the following enumeration:
• Open / Close (depends on opening direction)
• Min / Max (depends on Min/Max settings)
• Stop