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262/617
Building Technologies Division
6.12.5
Generation of common flow temperature setpoint
The controller collects all valid heat requests from the consumers (heating circuits 1...3,
DHW, instantaneous water heater, external requests 1...3) and classifies them
according to their priorities. A maximum selection is made between requests for heat
received from the heating circuits and external requests, which means that the highest
temperature value called for becomes the common flow temperature setpoint. Requests
for heat from DHW heating equipment are always given priority over other requests,
thus enabling them to also let a temperature value lower than that demanded by the
heating circuit and external consumers become the common flow temperature setpoint.
6.12.6
Generation of boiler temperature setpoint
The boiler temperature setpoint represents the basis for control of the burner and is
primarily dependent on the common flow temperature setpoint. If no request for heat
from the consumers is active, there is also no valid setpoint. For the switch-on threshold
in Standby mode, the temperature of parameter Setpoint frost protection (2217) is used.
Whenever the burner is put into operation because there is a request for heat from the
consumers, or because of the Frost protection function, the boiler temperature setpoint
is limited downward to at least the adjusted minimum boiler temperature. A number of
other functions can also influence the boiler temperature setpoint, either permanently or
temporarily (functions Manual control, Chimney sweep, or Heat generation lock).
T
°C
90
80
70
60
50
40
30
20
20
10
Figure 51: Generation of boiler temperature setpoint
Line no.
Meaning
8704
TAgem
Composite outside temperature
8744
TVw
Flow temperature setpoint of HC 1 (including setpoint increase, if any)
8774
TVw
Flow temperature setpoint of HC 2 (including setpoint increase, if any)
TKw
Boiler temperature setpoint
User Manual LMS14...
6 The settings in detail
TK
w
8744
0
-10
8774
-20
-30
8704
CC1U7471en
28.01.2015
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