Basic Documentation

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en
Building Technologies Fan speed controller, demand-controlled (basic type P) 03.10.2011
23.6 Air volume flow balancing
Forced control signals on the ventilation unit to set maximum air volume is required
to setup the air volume. You can override the volume flow controller (open) for the
corresponding air distribution zone regardless of the current available energy
demand signals for heating or cooling. Activating the "Simulation VAV supply air" or
"Simulation VVS extract air" switches on the supply air or extract air fan
respectively. The fans should be controlled to provide sufficient pressure prior to
the volume flow controller with the highest pressure loss so that even it can
achieve the maximum volume flow.
Procedure: Air volume flow balancing
 All devices are installed and commissioning is completed.
 Communications between the devices is operational and all zone settings
(geographical zone/air distribution zones) have been checked.
The VAV controller can control the corresponding room groups through forced
controlled of the air volume flow balancing.
The selection "Vmax" opens all VAV dampers for the corresponding air distribution
zone. This allows you to make the optimum settings for required air flow.
To exit the simulation, select "---". This resets the simulation mode.
Main menu > Air flow balancing >
Operating line Comments
Simulation VAV supply air ----, Vmax
Simulation VAV extract air ----, Vmax
The fault message "Simulation VAV supply air" or "Simulation VAV extract air" are
sent while simulating the volume flow controller.
No. Text Effect
3931 Simulation VAV supply air Non urgent message; must not be
acknowledged.
3932 Simulation VAV extract air Non urgent message; must not be
acknowledged.
23.7 General commissioning notes
Observe the following during commissioning:
 Setting values dependent on time, such as the pre-command of fire protection
dampers or dampers, switch-on delay, fans, ramp-up time and other setting
values that may have an impact on plant start-up behavior.
 Time-related specifications such as overshoot time when using electric heating
coils.
 Conduct function and communication tests of room control and the
corresponding volume flow controllers.
 KNX communications between the primary air handling unit and individual room
control: Data exchange of heat and refrigeration demand signals and request
signals (temperature or pressure control) are checked and fully operational.
 Ensure when switching on the primary air handling unit that the volume flow
controller is open and the fans cannot start when the dampers are closed.
Failure to comply with these items may result in damage to the aggregates and
plant parts!
Prerequisites
Forced control
Fault status messages