Daikin Altherma 3 GEO Series Installer's Reference Manual page 83

3°C Fixed hysteresis to prevent too much switching between
heat pump system and auxiliary boiler
a Auxiliary boiler active
b Auxiliary boiler inactive
If the outdoor
temperature...
Space heating by
the heat pump
system...
Drops below T Stops
calc
Rises above T +3°C Starts
calc
INFORMATION
▪ The bivalent operation function has no impact on the
domestic water heating mode. The domestic hot water
is still and only heated by the indoor unit.
▪ The permission signal for the auxiliary boiler is located
on the EKRP1HB (digital I/O PCB). When it is
activated, the contact X1, X2 is closed and open when
it is deactivated. See illustration below for the
schematic location of this contact.
X2M
X1M
YC Y1 Y2 Y3 Y4
# Code
9.C.3 [C-03] Range: –25°C~25°C (step: 1°C)
9.C.4 [C-04] Range: 2°C~10°C (step: 1°C)
The higher the value of [C‑04], the higher
the accuracy of the switch-over between
the heat pump system and the auxiliary
boiler.
To determine the value of [C‑03], proceed as follows:
1 Determine the COP (= coefficient of performance) using the
formula:
Formula
COP = (Electricity price / gas
(a)
price) × boiler efficiency
(a) Make sure to use the same units of measurement for the
electricity price and gas price (example: both c€/kWh).
2 Determine the value of [C‑03] using the graph:
EGSAH/X06+10DA9W(G)
Daikin Altherma 3 GEO
4P569820-1A – 2019.09
Then...
Bivalent signal for
the auxiliary boiler
is...
Active
Inactive
OFF ON
SS1
Description
Example
If:
▪ Electricity price: 20 c€/kWh
▪ Gas price: 6 c€/kWh
▪ Boiler efficiency: 0.9
Then: COP = (20/6)×0.9 = 3
COP
6
5
4
3
2
1
0
-14 -12 -10 -8 -6 -4 -2
Example:
a [C‑03]=2.5 in case of COP=3 and LWT=35°C
b [C‑03]=10.5 in case of COP=3 and LWT=55°C
NOTICE
Make sure to set the value of [5‑01] at least 1°C higher
than the value of [C‑03].
Electricity prices
INFORMATION
Electricity price can only be set when bivalent is ON
([9.C.1] or [C-02]). These values can only be set in menu
structure [7.5.1], [7.5.2] and [7.5.3]. Do NOT use overview
settings.
INFORMATION
Solar panels. If solar panels are used, set the electricity
price value very low to promote the use of the heat pump.
# Code
[7.5.1] N/A User settings > Electricity price
> High
[7.5.2] N/A User settings > Electricity price
> Medium
[7.5.3] N/A User settings > Electricity price
> Low
Alarm output
Alarm output
# Code
Alarm output: Indicates the logic of the
[9.D] [C–09]
alarm output on the digital I/O PCB
during malfunctioning.
▪ 0 Abnormal: The alarm output will be
powered when an alarm occurs. By
setting this value, a distinction is made
between the detection of an alarm,
and the detection of a power failure.
▪ 1 Normal : The alarm output will NOT
be powered when an alarm occurs.
See also table below (Alarm output
logic).
Alarm output logic
[C-09] Alarm
0 Closed output
1 Open output
10 Configuration
0 2 4 6 8 10 12 14
2.5 (a) 10.5 (b)
Description
Description
No alarm No power
supply to unit
Open output Open output
Closed output
Installer reference guide
83