Expert area
Part 3: General function description
36
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If the room temperature factor is "0", the pump
continues to run during the reduced operation
period after a one-off heating demand.
Switched according to heating limits
If the outside temperature that is measured and
calculated by the controller exceeds the heating limit
specified here by 1K (= 1°C), heating is disabled, the
pumps switch off and the mixers are closed. The heating
is enabled again when the outside temperature drops
below the set heating limit.
T-Limit Day => applies during heating times
T-Limit Night => applies during reduction times
Delayed pump switch-off
In the case of switch-off of the circulation pumps, the
circulation pumps are not switched off until 5 minutes
later if one of the burners was on during the last 5
minutes before the switch-off instant.
Pump blocking protection
The controller effectively prevents the pumps blocking
following longer periods out of operation. The integrated
protection function switches on all pumps which have not
been in operation during the past 24 hours for 5 seconds
at 12:00 hours every day.
Mixer motor blocking protection
If the mixer has not moved for 24 hours it is fully
opened at approximately 03:00 hrs. (once only). The
heating circuit pump is switched off during this time.
The maximum flow temperature is monitored. Cancelled
at maximum flow temperature – 5K.
Cooling mode - refrigerating machines
If a refrigerating machine is present, cooling mode can be
activated using the operating mode selector switch. =>
Hot water loading is only possible by means of the
conventional heat generators.
If a bypass valve for cooling operation (MF) is activated,
the bypass valve is switched in the Cooling operational
mode.
The refrigerating machines and associated HS pumps are
switched on when required by the heating circuits until
the return flow temperature has fallen below the desired
temperature [T-Return cooling]. The switching hysteresis
is 2K.
Cooling mode - heating circuit
In the Cooling operating mode, the temperature [T-Flow
Cooling] is adjusted via the mixer in the heating circuit
flow. Special functions (T-Flow Cooling):
OFF = Heating circuit is not cooled (Mixer Valve Closed,
Pump Off)
CLOSE = Mixer valve as bypass valve (Mixer Valve
Closed, Pump On)
The heating circuits reverse the adjustment of the mixing
valve. When enabled, the mixer controls the temperature
to the temperature [T-Flow Cooling] (see description of
parameters).
The pumps are switched according to the parameters set
for heating operation. In the case of room control, the
pumps are operated according to the set temperature for
cooling mode [T-Room Cooling].
Weather dependent enabling of cooling:
Cooling mode is enabled when the set outside
temperature [T-Outside Cool] is exceeded. Cooling
operation is set again 1K below the limit temperature.
Room temperature dependent enabling of cooling:
Cooling operation (heating circuit enabling) is enabled
when the temperature [T-Room cooling] is exceeded.
Cooling operation ends 2K below the set temperature.
If both conditions for enabling are set, both of these
conditions must be met for cooling mode to be enabled.