Siemens AEROGYR RWI65.01 - Frost Protection

Siemens Building Technologies CM2N3205E / 05.2001
Landis & Staefa Division 5/18
Application with HR system
Y
[%]
100 Y10 Y30
Y20
SD
T
w
h
w
c
X
P1
T
n1
X
P3
T
n3
X
P2
T
n2
3205D05E
(DtPnt 21)
(DtPnt 20)
SA
SA: Data point 20 "Switching interval"
SD: Data point 21 "Switching differential"
For ventilating and air conditioning plants with hot water air heater batteries. Frost
protection operation is selected with DIL switch 8 (water). Frost protection is used to
• protect the air heater battery against freezing
• facilitate plant startup at low outside temperatures
All parameters for frost protection are factory-set and can be changed: Response
temperatures, set values, P-bands and integral action times. The frost protection
concept functions with both kinds of temperature acquisition (in the water circuit or at
the air heater battery's outlet). The protective actions are the following:
• Continuous opening of heating valve, activation of circulating pump
• Switching off the fan or closing the air damper
• Maintaining the temperature when the fan is switched off (on the water side only)
• Fault status signal in the event of risk of frost
To ensure frost protection, the use of the following sensors is required:
• QAD22.../QAE21.9 for temperature acquisition in the water circuit
• QAF63... for temperature acquisition at the battery's outlet
Y
[ % ]
100 100
Y
[ % ]
00
TQ
w
w
Zt
Q23/Q24 Q13/Q14
Y10(P) Y10(PI)
Zt
Q13/Q14
2 K
I
Y
[ % ]
100
0
T
Y10(P)
Zt
Q13/Q14
Xpn
2K
w
wn
w
w
X
pd
½ X
pd
3205D14E
Plant ON
Air-/water side
Water side Air side
Plant OFF
T Temperature in air heater battery circuit or air temperature directly after the air heater battery
Q Load
Y Manipulated variable
Y10 Control command at heating valve
Q13/Q14 Relay output "Pump"
Q23/Q24 Relay output "Fan/air damper"
X
pd
P-band "Frost protection controller" (data point 9)
X
pn
P-band "Standby controller" (data point 10)
w
w
Frost alarm value (data point 7)
w
wn
Set value "Standby controller" (data point 8)
Zt Min. running time of circulating pump (data point 52)
Function diagramm 2
Frost protection