8 Configuration
Installer reference guide
66
EPGA11~ EAVH/9W
Daikin Altherma – Low temperature split
4P556070-1 – 2019.02
#
Code
Description
[9.C.1]
[C-02]
Bivalent: Indicates if the space heating is
also performed by means of another heat
source than the system.
▪ 0 No: Not installed
▪ 1 Yes: Installed. The auxiliary boiler
(gas boiler, oil burner) will operate
when the outdoor ambient temperature
is low. During bivalent operation, the
heat pump is turned off. Set this value
in case an auxiliary boiler is used.
▪ If Bivalent is enabled: When the outdoor temperature drops below
the bivalent ON temperature (fixed or variable based on energy
prices), the space heating by the indoor unit stops automatically
and the permission signal for the auxiliary boiler is active.
▪ If Bivalent is disabled: Space heating is only done by the indoor
unit within the operation range. The permission signal for the
auxiliary boiler is always inactive.
The switch-over between the heat pump system and the auxiliary
boiler is based on the following settings:
▪ [C‑03] and [C‑04]
▪ Electricity and gas prices ([7.4.5.1], [7.4.5.2], [7.4.5.3], and [7.4.6])
[C‑03], [C‑04], and
T
calc
Based on the settings above, the heat pump system calculates a
value T
calc
, which is variable between [C‑03] and [C‑03]+[C‑04].
T
A
T
calc
[C-03]+[C-04]
3°C
[C-03]
a
b
T
A
Outdoor temperature
T
calc
Bivalent ON temperature (variable). Below this
temperature, the auxiliary boiler will always be ON. T
calc
can
never go below [C‑03] or above [C‑03]+[C‑04].
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…
Then…
Space heating by
the heat pump
system…
Bivalent signal for
the auxiliary boiler
is…
Drops below T
calc
Stops
Active
Rises above T
calc
+3°C Starts
Inactive
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.
YC Y1 Y2 Y3 Y4
X1
X2
X3
X4
OFF ON
X2M
SS1
X1M
#
Code
Description
N/A
[C-03]
Range: –25°C~25°C (step: 1°C)
N/A
[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
Example
COP = (Electricity price / gas
price)
(a)
× boiler efficiency
If:
▪ Electricity price: 20 c€/kWh
▪ Gas price: 6 c€/kWh
▪ Boiler efficiency: 0.9
Then: COP = (20/6)×0.9 =
3
(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:
-14
0
1
2
3
4
5
6
-12
-10
-8
-6
-4
-2
0
2
4
6
8
10
12
14
COP
10.5 (b)
2.5 (a)
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 and gas prices
INFORMATION
To set electricity and gas price values, do NOT use
overview settings. Set them in the menu structure instead
([7.4.5.1], [7.4.5.2], [7.4.5.3], and [7.4.6]). For more
information on how to set the energy prices, see the
operation manual and the user reference guide.
Summary of Contents for Altherma EAVX-D9WG
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