Daikin EWYA004D2V3P Installer's Reference Manual page 173

EWAA004~008D + EWYA004~008D
Packaged air-cooled water chillers
and packaged air to water heat pumps
4P688013-1B – 2022.09
# Code
[9.C.1] [C-02]
▪ 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 heat pump stops automatically and the permission signal for the
auxiliary boiler is active.
▪ If Bivalent is disabled: Space heating is only done by the heat pump 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 price: [7.5.1], [7.5.2], [7.5.3]
▪ Gas price: [7.6]
[C‑03], [C‑04], and T
calc
Based on the settings above, the heat pump system calculates a value T
variable between [C‑03] and [C‑03]+[C‑04].
3°C
a
b
T [C-03]+[C-04]
[C-03]
calc
T Outdoor temperature
A
T Bivalent ON temperature (variable). Below this temperature, the auxiliary boiler will
calc
always be ON. T
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...
Drops below T
calc
Rises above T +3°C
calc
INFORMATION
The permission signal for the auxiliary boiler is located on the EKRP1HBAA (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.
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 in space heating when
the outdoor ambient temperature is low.
During bivalent operation, the heat pump will
run in domestic hot water operation when tank
heat-up is required, or is turned OFF. Set this
value in case an auxiliary boiler is used.
T
A
can never go below [C‑03] or above [C‑03]+[C‑04].
calc
Space heating by the heat
pump system...
Stops
Starts
11 Configuration
|
Description
, which is
calc
Then...
Bivalent signal for the
auxiliary boiler is...
Active
Inactive
Installer reference guide
173