External Sensor Input B1-M; Automatic Heating /Cooling Changeover; Remote Heating /Cooling Changeover; Summary B1-M And P22 - Siemens RDF210 Manual

External sensor input B1-M

Automatic heating /
cooling changeover
Remote heating /
cooling changeover
External room or
return air temperature
sensor
Summary
B1-M and P22
Building Technologies
HVAC Products
With the RDF210, a return air / external room temperature sensor or heating / cooling
changeover sensor can be connected to terminal B1-M. The function of this sensor
input is determined by parameter P22.
Sensor input B1-M is not galvanically separated from the AC 230 V mains supply.
Therefore, only a cable temperature sensor and wiring with sufficient insulation must be
used.
When P22 is set to "Automatic H/C changeover", the sensor input acts to ensure auto-
matic heating / cooling changeover. The water temperature acquired by the changeover
sensor (QAH11.1 + ARG86.3) is used to switch from heating to cooling mode, or vice
versa. When the water temperature lies above 28 °C (parameter P24), the controller
switches to heating mode; below 16 °C (parameter P23), it switches to cooling mode. If,
immediately after switching on, the water temperature lies between the 2 changeover
points, the controller will start in heating mode. The water temperature is acquired at
30-second intervals and the operating state is updated.
Automatic H/C changeover
M
CM
T [°C]
W
HM
16 28
M Operating mode
T Water temperature
w
The QAH11.1 cable temperature sensor for automatic heating / cooling changeover can
be replaced by an external switch (suited for mains voltage) for manual remote change-
over:
B1
M
T °C
With parameter P99 (diagnostic value), automatic heating / cooling changeover can be
checked.
When parameter P22 is set to "Cooling only" or "Heating only", sensor input B1-M can
be used to connect an external room temperature (QAA32) or a return air temperature
sensor (QAH11.1). Changeover is automatic if a sensor is detected at the sensor input.
With parameter P98 (diagnostic value), the sensor status can be checked.
The following table summarizes the relation between parameter P22, external sensor
B1-M and variables which the controller uses for maintaining the temperature:
Parameter Variables:
P22 The controller....
is in H/C mode
Heating only
controls according
is in H/C mode
Cooling only
controls according to
Automatic
is in H/C mode
H/C change-
over controls according to
Room Temperature Controllers
CM Cooling mode
HM Heating mode
B1
T
M
QAH11.1 3058Z03
No sensor at
B1-M
Heating
Internal sensor
Cooling
Internal sensor
Heating
Internal sensor
Contact open heating mode
Contact closed cooling mode
QAH11.1/QAA32 at
B1-M
Heating
Sensor at B1
Cooling
Sensor at B1
depending on the tempera-
ture from sensor B1-M
Internal sensor
7/15
N3058en
10.01.2006