Hitachi RASC-4HNPE Service Manual page 117

6 Optional functions
Optional functions
Wave function setting (UE)
This function activates a continuous wave cycle for the control of input current (20 minutes at 100% of maximum
compressor current, and 10 minutes at the percentage which has been selected through external input signals on the
7-segment display (60%, 70%, 80% or 100%)) (CN1 or CN2).
This function can be activated when current control demand function is selected at one of the input terminal indications
,  and 3.
?
N O T E
• If no external input signals are set, the input current control is set at 100%.
• The minimum limit of running current control is according to the set value of the demand function.
Cold draft protection (Fb)
This function allows to reduce the compressor frequency when the discharge air temperature in the indoor unit falls
below 12ºC in cooling operation. This is done in order to avoid the direct discharge of cold air.
Depending on the setting of "Cold draft protection" function, the SVA (Solenoid valve for high pressure bypass) is turned
ON.
Setting condition Temperature (ºC)
0
1
2
Cancellation of hot gas bypass control (E)
When this function is selected, the activation of hot gas bypass circuit between compressor discharge and heat
exchanger inlet is not performed. The hot gas bypass circuit is intended to reduce the amount of frost at the heat
exchanger.
Enabling this function, the number of defrost cycles is reduced while slightly reducing the heating capacity.
Forced stoppage after defrost operation (d5)
This function allows to stop the indoor unit fans after defrost operation is finished. The indoor unit fan operation is started
again once 3-minute ON guard for indoor units has finished. Then, the heating operation is restarted.
It is helpful to avoid the direct discharge of cold air after defrost operation.
107 SMGB0091 rev.2 - 11/2015
Input current
(100%)
Input current
(60 to 80%)
- Not available (default setting).
Cold draft is prevented thanks to the compressor frequency control and turning ON
< 12
SVA (solenoid valve for high pressure bypass circuit).
< 12 Cold draft is prevented thanks to the compressor frequency control.
Condition
6