High-Temperature Air-To-Water Heat Pumps; Hysteresis; Control Of Circulating Pumps; Heat Circulating Pump/Antifreeze (Frost Protection - Dimplex WPM 2006 R Installation And Start-Up Instructions Manual

9.6
9.5.3

High-temperature Air-to-Water Heat Pumps

Only 1 compressor normally operates at external temperatures
over 10 °C. If the external temperature is under 10 °C and the
flow temperature is higher than 50 °C, both compressors are
enabled:
1 compressor is switched on initially followed shortly afterwards
by the 2nd compressor. If the request is no longer pending or a
block is activated, both compressors are switched off
simultaneously.

9.6 Hysteresis

The so-called hysteresis for the different requests can be set in
the "Settings" menu. The hysteresis forms a "neutral zone"
around the corresponding set temperature. If the current
temperature is lower than the reduced set temperature around
the hysteresis, the request is then recognised. This remains in
existence until the current temperature has overshot the upper
limit of the neutral zone. This results in a switching cycle around
the set value.
Hysteresis of the return set temperature
A hysteresis can be set around the return set temperature for the
heating request.

9.7 Control of Circulating Pumps

By controlling the heat, hot water or swimming pool circulating
pumps, it can be determined where the heat generated by the
heat pump should flow. Individual processing of different
requests enables the heat pump to be always operated with the
lowest possible flow temperature. This ensures energy-efficient
9.7.1

Heat Circulating Pump/Antifreeze (Frost Protection)

Two operating modes are possible for heat circulating pumps
which can be set in the "Settings" menu.
Heating pump optimization is set to "No": The heat circulating
pump always operates, with the exception of DHW heating,
swimming pool heating and in the "Summer" operating mode.
Heating pump optimization is set to "Yes": The heat circulating
pump continues to run for 30 minutes after a power up and after
switch-off of the heat pump.
If the heat circulating pump was switched off for more than 40
minutes or the return temperature has dropped below the set
value, it is switched on for 7 minutes to supply the return flow
sensor with the representative temperature of the heating circuit
again (flushing period).
Independent of the setting, the heat circulating pump always
operates in heating or defrost operation and when there is
danger of frost. In systems with several heating circuits, the heat
circulating pumps 2/3 have the same function.
9.7.2

Hot Water Circulating Pump

The hot water circulating pump (DHW loading pump) operates
during DHW heating. If a request for domestic hot water is made
during heating operation, the heat circulating pump is
deactivated and the hot water circulating pump is activated with
the heat pump running.
E-30
In respect of the power stage, the high-temperature heat pump
responds like a heat pump with 1 compressor in this temperature
range independent of the selection in the configuration menu, i.e.
there is no power stage 2.
If the conditions for switching to power stage 3 as specified in
Chap. 9.5.1 on p. 29 are fulfilled, the 2nd heat generator is
enabled.
If the hysteresis is large, the heat pump will operate longer,
whereupon the temperature fluctuations in the return flow are
correspondingly large. A smaller hysteresis reduces the
compressor runtimes and the temperature fluctuations.
NOTE
For panel heating with relatively flat characteristic curves, set a
hysteresis of approx. 1 K because a too larger hysteresis can prevent the
heat pump from switching on.
operation. With heat pumps for heating and cooling, additional
cold circulating pumps can be controlled (Chap. 12 on p. 34).
NOTE
Pump units with check valves maintain the specified flow direction.
ATTENTION!
To ensure that the antifreeze function of the heat pump works properly,
the heat pump manager must remain connected to the power supply and
the flow must be maintained through the heat pump at all times.
If a switchover is made from heating operation to DHW
preparation or swimming pool water preparation, the heat
circulating pump continues to run for at least 1 minute.
The heating pump operates
temperatures lower than 3 °C, at return temperatures lower than
15 °C and at temperatures lower than 6 °C on the flow sensor of
air-to-water heat pumps.
NOTE
In the summer operating mode, the heating pump operates for 1 minute
every 150 hours (this prevents the heating pump from sticking at the
beginning of the heating period).
In the case of heat pumps with additional heat exchangers and
Setting – Parallel heat - DHW set to "Yes", the hot water pump
operates parallel to the heating pump during heating operation
until the set maximum temperature is reached.
continuously at external