Daikin Altherma 3 H HT F Series Installer's Reference Manual page 42

5 | Application guidelines
Installer reference guide
42
▪ 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
Indoor/Auto/Boiler
A
K1A
N
B Boiler thermostat input
TI
A Auxiliary contact (normally closed)
H Heating demand room thermostat (optional)
K1A Auxiliary relay for activation of indoor unit (field supply)
K2A Auxiliary relay for activation of boiler (field supply)
Indoor Indoor unit
Auto Automatic
Boiler Boiler
NOTICE
▪
Make sure the auxiliary contact has enough differential or time delay to prevent
frequent changeover between indoor unit and auxiliary boiler.
▪
If the auxiliary contact is an outdoor temperature thermostat, install the
thermostat 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.
Setpoint of the auxiliary gas boiler
To prevent freeze-up of the water piping, the auxiliary gas boiler must have a fixed
setpoint ≥55°C, or a weather-dependent setpoint ≥T
T (°C)
min
60
50
40
30
20
10
0
–30 –25 –20
T Outdoor temperature
a
T Minimum weather-dependent setpoint for auxiliary gas boiler
min
Com
Indoor
X2M
35 30
K1A
K2A
–15 –10 –5
B TI
X Y
K2A
.
min
0 5
T (°C)
a
EPRA14~18DAV3+W1 + ETVH/X16S18+23DA6V+9W(G)
Daikin Altherma 3 H HT F
4P587502-1 – 2019.07