44
In the case of absolute priority, heating
circuit pumps
eQ
/
rR
/
tR
are switched off
and mixers
rT
/
tT
are closed. With mod-
ulating priority control of the heating cir-
cuits with mixer, heating circuit pumps
rR
/
tR
remain on, and mixers
rT
/
tT
close far enough to enable the boiler
water temperature set for cylinder heat-
ing to be reached. In this case, DHW cyl-
inder
qP
or
qR
and heating circuit with
mixer
rP
and
tP
are heated simultane-
ously.
DHW heating by the solar thermal
system
Solar circuit pump
wE
starts and DHW
cylinder
qR
is heated up, if the tempera-
ture differential between collector tem-
perature sensor
wQ
and cylinder temper-
ature sensor
qT
exceeds the start tem-
perature differential.
Pump
wE
is stopped according to the fol-
lowing criteria:
■ The actual temperature drops below
the stop temperature differential
■ Exceeding the electronic temperature
limit (up to 90 °C) set in the solar con-
trol module (type SM1)
wZ
■ The temperature selected at high limit
safety cut-out
qZ
(if installed) is
reached
Demands for the auxiliary function are
met by circulation pump
wR
.
Suppression of reheating of the DHW
cylinder by the boiler in conjunction
with solar control module (type SM1)
Reheating suppression takes place in
two stages.
Reheating DHW cylinder
qR
by boiler
1
is suppressed as soon as DHW cyl-
inder
qR
is heated by collectors
wP
. For
this, the set cylinder temperature for
reheating is reduced by boiler
1
. Sup-
pression remains active for a certain time
after solar circuit pump
wE
has been
switched off.
In the case of uninterrupted heating by
collectors
wP
(> 2 h) boiler
1
will only
reheat, if the set cylinder temperature
(coding address "67") selected at boiler
circuit control unit
2
is not achieved.
In control unit
2
, coding address "67"
defaults a third set DHW temperature
(setting range 10 to 95 °C). This value
must be below the first set DHW temper-
ature.
DHW cylinder
qR
will only be heated by
boiler
1
when this set value is no longer
achieved by the solar thermal system.
Function/system components
Code
Adjust Delivered con-
dition
Operation with LPG
82:1
82:0
System only with two heating circuits with mixer (with-
out unregulated heating circuit)
00:8
00:10
00:7
00:9
Commissioning, inspection, maintenance
Further details regarding the individual steps
(cont.)
5692 860 GB
Summary of Contents for CU3A
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