Operation Manual

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Siemens Schweiz AG User Manual CE1U2354en
HVAC Products Cooling circuit 23. August 2007
Controls The valve is used for control in heating and cooling mode.
Open
The valve is used for control in cooling mode and is open in heating
mode.
Dewpoint monitoring
Line no. Operating line
946 Dewpt monitor locking time
947 Flow setpt increase hygro
948 Start flow increase at R.H.
950 Flow temp diff dewpoint
When the connected dewpoint monitor detects the formation of condensation it
closes the contact, thereby
deactivating the cooling.
The "dewpoint monitor locking time" set here starts running as soon as the contact re-
opens. Cooling can only start after expiry of this locking time.
The dewpoint monitor must be assigned to the H.. input as "dewpoint monitor".
To prevent the formation of condensation due to excess indoor air humidity, a hygrostat
can be used to implement a
fixed increase in the flow temperature.
As soon as the air humidity rises above the value set on the hygrostat, the contact is
closed and the flow temperature setpoint is increased by the amount programmed here.
The hygrostat must be assigned to the H.. input as "Flow setpt increase hygro".
To prevent the formation of condensation due to excess indoor air humidity, a
0…10 V humidity measurement can be used to implement a
proportional increase in
the flow temperature
.
If the relative humidity in the room exceeds the value defined by "Start flow increase at
R.H." the flow temperature setpoint is increased proportionally. The start of the increase
(operating line 949) and the maximum increase (operating line 947) can be
programmed.
The humidity sensor must be assigned to the H.. input as "Relative room humidity 10V".
r. F. %
(dT TVKw)
BZ948
BZ947
100%
dT TVKw Flow setpoint increase
r.F. Relative humidity
BZ Operating line
The dewpoint temperature is determined on the basis of the relative humidity of the
indoor air and the associated room air temperature.
To prevent the formation of condensation on surfaces, a minimum limit is applied to the
flow temperature so that it remains above the dew point temperature by the value set
here (operating line 950).
The function can be disabled with the setting – – –.
The humidity sensor must be assigned to an H.. input as "Relative room humidity 10V",
and a room temperature sensor must also be available (assigned to the H.. input as
"Room temperature 10V" or room unit).
Dewpt monitor
locking time
Flow setpt increase hygro
Start flow increase at R.H.
Flow temp diff dewpoint