Daikin EKHBH016AA, Operation Manual

Page: 13 / 20

EKHBH/X016AA
Indoor unit for air to water heat pump and sanitary warm water tank for air to water heat pump system
4PW36977-1B
Operation manual
12
[3] Auto restart
When power returns after a power supply failure, the auto restart
function reapplies the user interface settings at the time of the power
supply failure.
Note that with the function disabled the schedule timer will not be
activated when power returns to the unit after a power supply failure.
Press the
pr button to enable the schedule timer again.
■
[3-00] Status: defines whether the auto restart function is
turned ON (0) or OFF (1).
[4] Backup heater operation and space heating off temperature
Backup heater operation
—
Applies only to units with optional
backup heater installed.
The operation of the backup heater can altogether be enabled or
disabled, or it can be disabled depending on operation of the booster
heater.
■
[4-00] Status: defines whether backup heater operation is
enabled (1) or disabled (0).
■
[4-01] Priority: defines whether backup heater and booster
heater can operate simultaneously (0), or if the booster
heater operation has priority over the backup heater
operation (1).
Space heating off temperature
■
[4-02] Space heating off temperature: outdoor temperature
above which space heating is turned off, to avoid
overheating.
[5] Equilibrium temperature and space heating priority
temperature
Equilibrium temperature — The 'equilibrium temperature' field
settings apply to operation of the optional backup heater. When the
equilibrium temperature function is enabled, operation of the backup
heater is restricted to low outdoor temperatures, i.e. when the
outdoor temperature equals or drops below the specified equilibrium
temperature. When the function is disabled, operation of the backup
heater is possible at all outdoor temperatures. Enabling this function
reduces the working time of the backup heater.
■
[5-00] Equilibrium temperature status: specifies whether the
equilibrium temperature function is enabled (1) or
disabled (0).
■
[5-01] Equilibrium temperature: outdoor temperature below
which operation of the backup heater is allowed.
Space heating priority temperature (applies only to installations
with a sanitary water tank) — The 'space heating priority
temperature' field settings apply to operation of the 3-way valve and
the booster heater in the sanitary water tank.
When the space heating priority function is enabled, it is assured that
the full capacity of the heat pump is used for space heating only
when the outdoor temperature equals or drops below the specified
space heating priority temperature, i.e. low outdoor temperature. In
this case the sanitary water will only be heated by the booster heater.
■
[5-02] Space heating priority status: specifies whether space
heating priority is enabled (1) or disabled (0).
■
[5-03] Space heating priority temperature: outdoor
temperature below which the sanitary water will be heated by
the booster heater only, i.e. low outdoor temperature.
■
[5-04] Set point correction for sanitary water temperature: set
point correction for the desired sanitary 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 sanitary water heating
Applies only to installations with a sanitary water tank.
The 'DT (delta temperature) for sanitary water heating' field settings
determine the temperatures at which heating of the sanitary 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 sanitary water temperature drops below the heat pump ON
temperature (
T
HP ON
), heating of the sanitary water by the heat pump
will be started. As soon as the sanitary water temperature reaches
the heat pump OFF temperature (
T
HP OFF
) or the user set point
temperature (
T
U
), heating of the sanitary 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.
NOTE It is therefore recommended to leave the auto restart
function enabled.
NOTE When the priority field setting is set to ON (1),
space heating performance of the system
might be decreased at low outdoor
temperatures, since in case of sanitary water
heating demand the backup heater will not be
available for space heating (space heating will
still be provided by the heat pump).
When the priority field setting is set to OFF (0),
make sure that electrical power consumption
does not exceed supply limits.
T
set
Sanitary 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 sanitary
water tank (55°C)
T
HP OFF
Heat pump OFF temperature
T
HP ON
Heat pump ON temperature
T
A
T
set
T
U
[5-03]
[5-04]
T
U
> T
HP MAX
T(
°
C)
70 T
U
50 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
50 T
HP MAX
38 T
HP ON
[6-00]
T
U
= 45
°
C
[6-01] = 2
°
C
[6-00] = 7
°
C
T
U
= 70
°
C
[6-01] = 2
°
C
[6-00] = 7
°
C