Siemens QAX850 - Internal sensor; Mounting and installation notes

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Siemens Master room unit QAX850 CE1N2722en
Building Technologies 28.08.2007
No. Parameter Range
P06 RV ON in heat or cool mode Heat/Cool
P07 Fan run ON after heat output turns Off 0…300 s
P08 Fan run ON after cool output turns Off 0…300 s
P09 FCU flush pipe time 120…600 s
P10 Zone Heat / Cool Inhibit Heat/Cool/No
P11 Water temp. heat mode changeover 22…32 °C
P12 Water temp. cool mode changeover 10…21 °C
P13 Fan auto-speed high range H:80…100 %
P14 Fan auto-speed medium range M:30…75 %
P15 Fan auto-speed low range L:1…15 %
P16 Window contact NO/NC
P17 2-p or 3-p control selection 2-p/3-p
P18 P-band in heat mode /Switching differential 0.5…10 K
P19 P-band in cool mode /Switching differential 0.5…10 K
P20 Integration time 0…60.0 min in
0.5 min steps
P21 3-p valve actuator running time 50…300 s
P22 Zone capacity weight None
Small
Medium
Large
P23 Ventilation in dead zone Off, H/C, C only
QAX850 internal sensor can be replaced by connecting an external NTC resistor
sensor (QAA32 or QAH11) to the RRV controller B1 input. In this case the QAX850
automatically recognizes and displays the external sensor value.
Mounting and installation notes
The QAX850 should be mounted in a location where the air temperature can be
measured as accurately as possible without getting adversely affected by direct solar
radiation or other heating or cooling sources. There is no need to consider air
temperature conditions if external sensor is connected to the RRV controller. In this
case the QAX850 would serve as a master control unit only.
• Mounting height is about 1.5 m above the floor.
• QAX850 must not be located in the direct path of air conditioning air flow.
• The unit can be fitted to a recessed conduit box.
• The specified ambient conditions must be complied with.
• Only authorized staff may disconnect the QAX850 unit from base plate.
• Do not mount in recesses, shelves, behind curtains or doors.
• Refer to Mounting Instructions M2721 included in packaging box.
When mounting the unit, fix the base-plate first and then make the electrical
connections. To avoid any damage during construction works only install QAX850 unit
Internal sensor