EKCBX/H008BBV3
Unit for air to water heat pump system
4PW66983-1C – 08.2011
Installation manual
29
[7] DT for booster heater and dual set point control
DT for booster heater
Applies only to installations with a domestic hot water tank.
When the domestic hot water is heated and the domestic hot water
set point temperature (as set by the user) has been reached, the
booster heater will continue to heat the domestic hot water to a
temperature a few degrees above the set point temperature, i.e. the
booster heater OFF temperature. These extra degrees are specified
by the domestic hot water step length field setting. Correct setting
prevents the booster heater from repeatedly turning on and off (i.e.
chattering) to maintain the domestic hot water set point temperature.
Note: the booster heater will turn back on when the domestic hot
water temperature drops [7-01] (field setting) below the booster
heater OFF temperature.
■
[7-00]
Domestic hot water step length: temperature
difference above the domestic hot water set point
temperature before the booster heater is turned off.
■
[7-01]
Hysteresis value booster heater: temperature
difference determining the booster heater ON temperature
(T
BH ON
). T
BH ON
= T
HP OFF
– [7-01]
Dual set point control
Applies only to installations with different heat emitter which require
different set points.
Dual set point control makes it possible to generate 2 different set
points.
■
[7-02] Dual set point control status: defines whether the dual
set point control is enabled (1) or disabled (0).
■
[7-03] Second set point heating: specifies the second set
point temperature in heating operation.
■
[7-04] Second set point cooling: specifies the second set
point temperature in cooling operation.
INFORMATION
■
Make sure that the domestic hot water set point is
according to your requirements.
Start with a low domestic hot water storage set point,
and only increase if you feel that the domestic hot
water supply temperature is not sufficient for your
requirements (this depends on your water using
pattern).
■
Make sure the domestic water is not heated
unnecessary. Start with activating automatic storage
during night (default setting). If it seems that the
scheduled storage domestic water heating during the
night is not sufficient for your requirements, an
additional scheduled reheat during daytime can be
set.
INFORMATION
If the schedule timer for booster heater (see the operation
manual) is active, the booster heater will only operate if
allowed by this schedule timer.
BH
Booster heater
HP
Heat pump. If heating up time by the heat pump takes too
long, auxiliary heating by the booster heater can take place
T
BH OFF
Booster heater OFF temperature (T
U
+ [7-00])
T
BH ON
Booster heater ON temperature (T
BH OFF
– [7-01])
T
HP MAX
Maximum heat pump temperature at sensor in domestic hot
water tank
T
HP OFF
Heat pump OFF temperature (T
HP MAX
– [6-01])
T
HP ON
Heat pump ON temperature (T
HP OFF
– [6-00])
T
DHW
Domestic hot water temperature
T
U
User set point temperature (as set on the user interface)
t
Time
t
T
BH ON
T
DHW
T
HP ON
T
HP OFF
T
HP MAX
T
U
T
BH OFF
[6-01]
[6-00]
[7-00]
[7-01]
T
U
= 70
°
C
[7-00] =
3
°
C
[6-01] =
2
°
C
[6-00] =
7
°
C
HP
BH
HP
5
10
20
30
40
41
48
50
60
71
70
73
WARNING
Be aware that the domestic hot water temperature will be
automatically increased (always) with the value selected in
field setting [7-00] compare to the user set point for
domestic hot water (T
U
). Refer to field setting [7-00] and
the operation manual to select preferable set point.
If this high water temperature can be a potential risk for
human injuries, a mixing valve (field supply) shall be
installed at the hot water outlet connection of the domestic
hot water tank. This mixing valve shall secure that the hot
water temperature at the hot water tap never rise above a
set maximum value. This maximum allowable hot water
temperature shall be selected according to the applicable
legislation.
INFORMATION
If the booster heater operation is limited ([4-03]=0), then
set point of field setting parameter [7-00] has only meaning
for powerful domestic water heating.
INFORMATION
The minimum value for booster heater ON
temperature (T
BH ON
) is 2°C (fixed) below heat pump
OFF temperature (T
HP OFF
).
INFORMATION
There is no indication available which set point is
active!
