Daikin EWYA004D2V3P Installer's Reference Manual page 38

6 | Application guidelines
Installer reference guide
38
▪ Make sure the return water to the heat pump does NOT exceed 60°C. To do so:
- Set the desired water temperature via the auxiliary boiler controller to
maximum 60°C.
- Install an aquastat valve in the return water flow of the heat pump. Set the
aquastat valve to close above 60°C and to open below 60°C.
▪ Install non-return valves.
▪ An expansion vessel is already pre-mounted in the outdoor unit. But for bivalent
operation, also make sure that there is an expansion vessel in the auxiliary boiler
loop. Otherwise when bivalent operation is running and if the Aquastat valve
would close, there would be no expansion vessel in the water circuit anymore.
▪ Install the digital I/O PCB (option EKRP1HBAA).
▪ Connect X1 and X2 (changeover to external heat source) on the digital I/O PCB to
the auxiliary boiler. See
4
source" [ 95].
▪ To setup the heat emitters, see
4
system" [ 25].
Configuration
Via the user interface (configuration wizard):
▪ Set the use of a bivalent system as external heat source.
▪ Set the bivalent temperature and hysteresis.
NOTICE
▪
Make sure the bivalent hysteresis has enough differential to prevent frequent
changeover between outdoor unit and auxiliary boiler.
▪
Because the outdoor temperature is measured by the outdoor unit air
thermistor, install the outdoor unit in the shadow so that it is NOT influenced or
turned ON/OFF by direct sunlight.
▪
Frequent changeover may cause corrosion of the auxiliary boiler. Contact the
manufacturer of the auxiliary boiler for more information.
Changeover to external heat source decided by an auxiliary contact
▪ Only possible in external room thermostat control AND one leaving water
temperature zone (see
▪ The auxiliary contact can be:
- An outdoor temperature thermostat
- An electricity tariff contact
- A manually operated contact
- ...
▪ Setup: Connect the following field wiring:
L
H
Outdoor/Auto/Boiler
A
K1A
N
B Boiler thermostat input
TI
A Auxiliary contact (normally closed)
"9.2.9 To connect the changeover to external heat
"6.2 Setting up the space heating/cooling
"6.2 Setting up the space heating/cooling
Com
Outdoor
X2M
35 30
K1A
K2A
system" [
B TI
X Y
K2A
EWAA004~008D + EWYA004~008D
Packaged air-cooled water chillers
and packaged air to water heat pumps
4P688013-1B – 2022.09
4
25]).