Specifications

Control Specification SiBE04-624
76 Function and Control
3.14.2 Control when Starting
Outline Obviously when the unit is switched on, some adjustments to the expansion valve opening have
to be made in order to prevent excessive heating or moisture.
Cooling
EV = K
evopf x ∆Fcom+ Kevopdce x DA+ Kevopdoa x DOA+ P5
Heating
In 2 min. from the operation starts.
EV = K
evopf
x ∆F
com
+ P
5
After 2 min. from the operation starts.
Ending Condition
After 6 minutes from the time compressor starts.
or
Discharge temperature +6 > condensation temperature > 36°C
K
evopf
: A constant depending on the outdoor unit type
P
5
: A constant depending on the outdoor unit type
K
evopdce
: A constant depending on the outdoor unit type.
K
evopdoa
: A constant depending on the outdoor unit type.
d
oaopf
: A constant
dd
oaopf
: A constant
D
A
: The room temperature.
D
OA
: The outdoor temperature.
∆F
com
: Compressor frequency change.
3.14.3 Control when Frequency is Changed
Outline Because the operation frequency is one of the variables in the calculation of the original opening
of the expansion valve, the opening will have to be recalculated when the operation frequency is
changed. During this recalculation, the target discharge temperature control will be deactivated.
Detail This control will engage when the operation frequency is changed during the target discharge
temperature control. When this happens, a 10 seconds timer is set. Once this timer expires, the
expansion valve opening is recalculated using the formulas below:
PHNHZ = PHNHZZ + KEVOPF x (FMK - FMKZ)
Where:
PHNHZZ = expansion valve opening before change
PHNHZ = expansion valve opening after change
KEVOPF = constant value (cooling:2.7, heating:2.0)
FMK = operation frequency after change
FMKZ = operation frequency before change
The expansion valve opening is only changed when FMK - FMKZ > 4.
D
OA
≤ d
oaopf
EV = K
evopf
x
∆
F
com
+ P
5
d
oaopf
< D
OA
≤ d
oaopf
+ dd
oaopf
EV = K
evopf
x
∆
F
com
+ P
5
+ K
evopdoa
x (D
OA
- d
oaopf
)
d
oaopf
+ dd
oaopf
< D
OA
EV = K
evopf
x
∆
F
com
+ P
5
+ K
evopdoa
x dd
oaopf