Essential Service Mode - Siemens SINAMICS G120 CU230P-2 HVAC Operating Instructions Manual

Functions
7.9 Application-specific functions
7.9.10

Essential service mode

The Essential Service Mode (ESM) function ensures that when required, the motor is
operated for as long as possible so that, for example, smoke gases can be extracted or
people affected by a fire can escape.
Application example
In order to improve air circulation in stairwells, frequently, a slight underpressure is
generated using ventilation control. With this control, a fire would mean that smoke gases
enter into the stairwell. This would then mean that the stairway would be blocked as escape
or evacuation route.
Using the Essential Service Mode function, the ventilation switches over to control an
overpressure. This prevents the propagation of smoke gases in the stairwell, thereby
keeping the stairs free as an escape route.
Activating the essential service mode function
The essential service mode is activated by interconnecting p3880 with a digital input of your
choice. Example: If you wish to activate the essential service mode with the digital input, set
p3880 = 722.3.
Note
Command source for the essential service mode
We recommend that the digital input for the essential service mode is not logically combined
with any other functions.
• The setting of the source for the essential service mode via p3880 is always referred to
• The essential service mode can only be switched on precisely from one source.
The last setpoint recognized is taken as the emergency setpoint in the factory setting. You
can use p3881 to define another value:
● P3881 = 0: Last recognized setpoint (factory setting)
● P3881 = 1: Fixed setpoint 15
● P3881 = 2: Analog setpoint
● P3881 = 3: Fieldbus
● P3881 = 4: Technology controller
If you specify the emergency setpoint via the analog setpoint, fieldbus or technology
controller, you must ensure the appropriate monitoring so that an alternative setpoint can be
used in the event of failure.
Possible forms of monitoring for the different setpoint sources:
● Analog setpoint: Using F03505
● Fieldbus status in r2043
● Technology controller r2349
252
the data set that is currently active.
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD