User Manual

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en
Building Technologies Sustained mode (basic type A) 03.10.2011
19.2 Sustained mode operation
The Precomfort setpoints determine switch-on/switch-off of sustained mode
(Precomfort); Economy setpoints determine switch on/switch-off of sustained mode
(Economy). The entire plant with all controllers switches on as soon as the main
controlled variable from the controller drops below or exceeds the switch-on value.
The switched on plant is controlled to Comfort setpoints. The fan speed can be set.
Corresponding setpoints must be set to extreme values if only one single main
controlled variable is desired (e.g.
Economy heating setpoint: 50 °C,
Economy cooling setpoint: 100 °C).
You can prevent the plant elements from being switched on or off too often via the
setting "Operating time min".
Main menu > Commissioning > Settings > .... or
Main menu > Settings > Operating mode >
Operating line Range Factory setting
Sustained mode time minimum 00.00...06.00 h.m 00.30 h.m
Sustained mode fan Speed 1, Speed 2 Speed 1
The following controls apply to switching on/off the plant by controller 1, controller
2, or controller 3:
 Mix air damper with normal control
 The speed-controlled fan with fixed speed for 2-speed operation is controlled
with maximum speeds (see section 10.1.4 "Variable-speed fan")
The followi
ng points apply to switching on/off the plant by the IAQ controller:
 The mixed air damper controls the damper setpoint (see section 16.2 "Open
outsid
e air damper (basic types A and P)")
 The speed-controlled fan without pressure control is controlled via the fan
setpoint (see section 16.5 "Increase fan speed (basic types A, P)")

Control of supply air and extract air fans:
 The supply air fan is always switched on when the plant is switched on by
sustained mode. The switch-on of the extract air fan depends on setting
parameter "Sustained/Recirculated air operation" (see section 10.1.13)

For 2-speed operation of fans and configured room/supply air or extract/supply
air cascade control, speed changeover may occur according to
heating/refrigeration demand (see section 11.6.3)

For 2-speed operation of fans and configured IAQ controller, speed changeover
may occur according to indoor air quality(see section 16.4)
Sust
ained mode (Precomfort) and sustained mode (Economy) for heating is
automatically set to inactive via bus at active heating, when the ventilation
controller RMU7..B is controlled in the same room together with a heating
controller RMH760 (see section 11.8 "Room control combinations with heating
contr
oller").
Sustained mode is also automatically set to inactive when using the input contact
"Casc/Const" if closed.
Setting values
Notes