Installation manual
53
EKHBH/X008BB
Indoor unit for air to water heat pump system
4PW62570-1A – 01.2011
5.
O
VERVIEW
OF
THE
INDOOR
UNIT
5.2.
Main components
The backup heater (2) consists of an electrical heating element in the
backup heater vessel that will provide heating capacity to the water
circuit in case of malfunction ot he outdoor unit. In this application
with restricted power supply condition mode, the backup heater
should be considered as emergency backup heater (2).
6.
I
NSTALLATION
OF
THE
INDOOR
UNIT
6.8.
General precautions concerning water circuit
Checking the water volume and expansion vessel
pre-pressure
The unit is equipped with an expansion vessel of 10 litre which has a
default pre-pressure of 1 bar.
To assure proper operation of the unit, the pre-pressure of the
expansion vessel might need to be adjusted and the minimum and
maximum water volume must be checked.
1
A minimum water volume is required to prevent that the water
temperature drops too much during defrost (low ambient
temperature).
If the water volume is too low, 2 problems can occur:
1
The water temperature drops too much during defrost and
defrost stops to protect the plate heat exchanger against
freezing.
2
The compressor does not start up after the defrost cycle
because the water temperature is too low.
In both cases the backup heater will operate instead of the
compressor to increase the water temperature.
When the water temperature is high enough, the backup heater
stops and the compressor restarts.
The minimum required water volume in the system is 20 l.
However, to minimize emergency backup heater operation it is
highly recommended to have a water volume of 40 l.
7.
E
LECTRICAL
WIRING
WORK
7.3.
System overview of field wiring
Connection to a benefit kWh rate power supply
For applications with restricted power supply condition mode, it is not
recommended to connect the system to a benefit kWh rate power
supply.
All items related to benefit kWh rate power supply should be
neglected.
8.
S
TART
-
UP
AND
CONFIGURATION
8.5.
Re-start at low outdoor ambient temperatures
When re-starting at low ambient temperature, it is important to
ensure that the unit operates within its operation range as soon as
possible (water temperature
≥
30°C) by reducing the load as much as
possible during start-up. This procedure is applicable whenever the
water temperature is out of the operation range (e.g. after long period
of stand still, ...).
8.9.
Field settings
[2] Disinfection function
Applies only to installations with a domestic hot water tank.
The disinfection function disinfects the domestic hot water tank by
periodically heating the domestic hot water to a specific temperature.
■
[2-00] Operation interval: day(s) of the week at which the
domestic hot water should be heated.
■
[2-01] Status: defines whether the disinfection function is
turned on (1) or off (0).
■
[2-02] Start time: time of the day at which the domestic hot
water should be heated.
■
[2-03] Set point: high water temperature to be reached.
■
[2-04] Interval: time period defining how long the set point
temperature should be maintained.
T
DHW
Domestic hot water temperature
T
U
User set point temperature (as set on the user interface)
T
H
High set point temperature [2-03]
t
Time
INFORMATION
If the heating load is higher than the backup heater
capacity, the water temperature can not increase. In
this case refer to
"8.5. Re-start at low outdoor ambient
NOTICE
Repeated forced defrost stops can in some cases
cause severe ice build-up on the outdoor unit. This will
lead to reduced unit performance.
A
PPENDIX
(for restricted power supply condition mode only)
CAUTION
The disinfection function field settings must be configured
by the installer according to the applicable legislation.
00.00
22.00
24.00
01.00
23.00
t
T
DHW
T
H
T
U
[2-02]
[2-03]
[2-04]
