7 sys tem-wide functions 57, 2 frost pro tec tion 57, 3 for ced ope ra tion of the pumps 57 – Samson 5476 User Manual
Page 57: 4 return flow tem pe ra ture limi ta tion 57, For ced ope ra ti on, pumps 57, Frost pro tec ti on 57, Re turn flow tem pe ra tu re li mi ta tion 57, Sum mer time/win ter time chan geo ver 57, System-wide functions, Automatic summer time/winter time changeover
7
System-wide functions
7.1
Automatic summer time/winter time changeover
The clock is automatically adjusted on the last Sunday in March at 2.00h and on the last Sunday
in October at 3.00h.
Function
WE
Configuration
Summer time/winter time changeover
ON
FB5 = ON
7.2
Frost protection
When outdoor temperatures below 3 °C occur, the heating circulation pumps UP1 and UP2 are
switched on. The controllers regulates the temperature to a flow temperature set point of 20 °C.
The circulation pump for the DHW circuit is likewise switched on. Outside the DHW heating
times-of-use, the temperature in the DHW storage tank is additionally kept at 5 °C, provided a
storage tank thermostat is not used. In conjunction with a storage tank thermostat, the frost pro-
tection function does not work outside the times-of-use.
Note!
The frost protection function is not activated when manual mode is selected at the mode switch.
7.3
Forced operation of the pumps
When the heating circuit pumps have not been activated for 24 hours, forced operation of the
pumps is started between 00.00h and 00.01h. This is done to avoid that the pumps get stuck
when they are not operated for a longer period of time. The forced operation of the storage tank
or heat exchanger charging pump is operated between 00.01h and 00.02h.
7.4
Return flow temperature limitation
The temperature difference between the flow and return flow indicates how well the energy is
used: the greater the difference, the higher the efficiency. A return flow sensor is sufficient to
evaluate the temperature difference when the flow temperatures are preset. The return flow tem-
perature can be limited either to a value depending on the outdoor temperature (variable) or to
a fixed set point. When the temperature measured at return flow sensor RüF exceeds the limit
value, the set point of the flow temperature (flow temperature of the heating system, charging
temperature) is reduced. As a result, the primary flow rate is reduced and the return flow tem-
perature falls. The
Limiting factor determines how strongly the controller responds when the limit
values are exceeded in either direction.
EB 5476 EN
57
System-wide functions