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Siemens Building Technologies
Basic Documentation RVA47.320
CE1P2379E
HVAC Products
Description of the heating engineer settings
15.07.2002
Decrease:
Switching differential will become smaller
•
Pumps are switched on and off
more often
•
Room temperature varies within a
narrower
band
Increase:
Switching differential will become greater
•
Pumps are switched on and off
less often
•
Room temperature varies within a
wider
band
With pump heating circuits, the amount of heat supplied is controlled by switching the
pumps on and off. This is accomplished with two-position control by means of the room
temperature's switching differential.
Room temperature acquisition requires a room unit.
OFF
ON
P
°C
TRx
TRw+SDR
23
71
D
02
TRw
t
°C
23
79Z
19
ON
OFF
w
TRx
P
[ ]
Pump ON
TRx =
TRw
Pump OFF
TRx =
TRw + SDR
4.30 Minimum
limitation
of the flow temperature
setpoint
•
Prevents too low flow temperatures
Minimum and maximum limitation define the range within which the flow temperature
setpoint may vary.
Room temperature
control
Note
Functioning:
Switching differential
Benefit
Description
TRx Actual value of the room temperature
TRw Room
temperature setpoint
SDR Switching
differential of room temperature
P
Pump (ON / OFF)
w Setpoint
Switch-on point
Switch-off point
Legend
TRx
Actual value of the room temperature
TRw
Room temperature setpoint
SDR
Switching differential of room
temperature
ON Switch-on
point
OFF Switch-off
point
t Time
P Pump