E(D/B)(H/L)Q011~016BB
Unit for air to water heat pump system
4PW67904-1 – 01.2011
Installation manual
38
[7] DT for booster heater and dual set point control
DT for booster heater (only for EKHW*)
Applies only to installations with a domestic hot water tank
(1)
.
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.
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
■
[7-01]
Hysteresis value booster heater: temperature
difference determining the booster heater ON temperature
(T
BH ON
). T
BH ON
=T
BH OFF
–[7-01]
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.
(1) Only applicable for tank with built-in electrical booster heater (EKHW*).
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.
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] compared 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 domestic hot 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
).
