Operation manual
13
E(D/B)(H/L)Q011~0W1
Unit for air to water heat pump system and options
4PW51122-1
■
[5-04] Set point correction for domestic hot water
temperature: set point correction for the desired domestic hot
water temperature, to be applied at low outdoor temperature
when space heating priority is enabled. The corrected
(higher) set point will make sure that the total heat capacity of
the water in the tank remains approximately unchanged, by
compensating for the colder bottom water layer of the tank
(because the heat exchanger coil is not operational) with a
warmer top layer.
[6] DT for domestic water heating
Applies only to installations with a domestic hot water tank.
The 'DT (delta temperature) for domestic water heating' field settings
determine the temperatures at which heating of the domestic water
by the heat pump will be started (i.e., the heat pump ON
temperature) and stopped (i.e., the heat pump OFF temperature).
When the domestic hot water temperature drops below the heat
pump ON temperature (
T
HP ON
), heating of the domestic hot water by
the heat pump will be started. As soon as the domestic hot water
temperature reaches the heat pump OFF temperature (
T
HP OFF
) or
the user set point temperature (
T
U
), heating of the domestic water by
the heat pump will be stopped (by switching the 3-way valve).
The heat pump OFF temperature, and the heat pump ON
temperature, and its relation with field settings [6-00] and [6-01] are
explained in the illustration below.
■
[6-00] Start: temperature difference determining the heat
pump ON temperature (
T
HP ON
). See illustration.
■
[6-01] Stop: temperature difference determining the heat
pump OFF temperature (
T
HP OFF
). See illustration.
[7] Domestic hot water step length
Applies only to installations with a domestic hot water tank.
When the domestic 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 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 2°C (fixed value) 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.
T
set
Domestic hot water set point temperature
T
U
User set point (as set on the user interface)
T
A
Ambient (outdoor) temperature
Space heating priority
T
U
User set point temperature (as set on the user interface)
T
HP MAX
Maximum heat pump temperature at sensor in domestic hot
water tank (55°C)
T
HP OFF
Heat pump OFF temperature
T
HP ON
Heat pump ON temperature
NOTE
T
HP MAX
is a theoretical value. In reality the maximum
tank temperature that can be reached with the heat
pump is 53°C. It is advised to select T
HP OFF
not higher
than 48°C in order to improve performance of the heat
pump during domestic water heating mode.
T
A
T
set
T
U
[5-03]
[5-04]
T
U
> T
HP MAX
T(
°
C)
70
T
U
55
T
HP MAX
48
T
HP OFF
41
T
HP ON
[6-01]
[6-00]
T
U
< T
HP MAX
T(
°
C)
45
T
U
= T
HP OFF
55
T
HP MAX
38
T
HP ON
[6-00]
T
U
= 45
°
C
[6-01] = 7
°
C
[6-00] = 7
°
C
T
U
= 70
°
C
[6-01] = 7
°
C
[6-00] = 7
°
C
NOTE
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
– 2°C)
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
NOTE
If the booster heater operation is limited
([4-03]=0), then set point of field setting parameter
[7-00] has no meaning.
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]
T
U
= 70
°
C
[7-00] =
3
°
C
[6-01] =
7
°
C
[6-00] =
7
°
C
HP
BH
HP
0
10
20
30
40
41
48
55
60
71
70
73
