Basic Documentation

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Siemens Universal controllers RMU710B, RMU720B, RMU730B CE1P3150en
Building Technologies Heating/cooling changeover 03.10.2011
27.3 Effect of function H/C
The effect of preselected H/C depends on the type of changeover and if it occurred
locally or via signal from the bus.
27.3.1 Lock sequences at sequence controller
In operating mode "Heating", the sequence assigned to function block
"Refrigeration demand" are locked.
In operating mode "Cooling", the sequence assigned to function block "Heat
demand" are locked.
Lock for "Cooling" Lock for "Heating".
27.3.2 Heat / refrigeration demand
In operating mode "Heating", the refrigeration demand relay is locked, refrigeration
demand set continuously to 0%, and no refrigeration demand signal is sent to the
bus.
In operating mode "Cooling", the heat demand relay is locked, heat demand set
continuously to 0%, and no heat demand signal is sent to the bus.
27.3.3 Locking time
To prevent the refrigeration machine from switching on immediately following
switch-off of heat generation, a locking time can be set.
Control is locked during the locking time; as a result, no heat or refrigeration
demand is generated or signaled.
Excessive inlet temperature at the refrigeration machine can damage the
refrigeration machine.
Main menu> Commissioning > Settings > Heating/cooling ch'over >
Operating line Range Factory setting
Locking time 00.00...23.50 h.m 00.30 h.m
The locking time acts also after a power drop-related switch-off of the device and
when exiting the Commissioning menu.
Example
Setting values