Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 1041

(ii) When SW on the PCB of indoor unit is turned on at the field.
5-1
Input signal to CnT becomes valid at OFF → ON only and the motion of air conditioner [ON/OFF] is inverted.
CnT Input
A Unit
B Unit
(14) Snow Fan Control
Set the dip switch SW
3-3
is operated at the Hi speed for 10 seconds every 10 minutes when the outdoor air temperature drops below 3°C.
(15) Control of Coompressor Capacity
When the load is set as low as less than 35Hz of full load operation frequency
load area, a hot gas bypass
Also, when the full load conversion frequency comes to over 35Hz
during a hot gas bypass operation, a full load operation is selected.
The compressor starts with a hot gas bypass all the time and, after
15 seconds, selects the load and the frequency according to the
demand(decision) frequency.
Notes (1) Full load operation frequency:
35Hz~95Hz(every 5Hz)
(2) Hot gas bypass operation frequency:
35Hz~45Hz(every 5Hz)
(3) The change-over occurs when 5 minutes of more
operation time has passed.
(16) High pressure control
The high pressure control consists of the HP protection, HP-A control, HP-B control and LP control and the order of priority
among them is assigned as HP protection >HP-A > LP > HP-B down > HP-B up.
HP protection
Pressure switch [If 63H1: 3.24 open/2.65 close MPa (33 Open/27 close kgf/cm
operation is stopped due to the error and the check and indication (Remote controller: E40, indoor LED-green; repeated flickers,
red: dark, outdoor LED-green; reperted flickers, red; 3 flickers) are performed. In case of initial operation, however, the
compressor is stopped and after a delay of 3 minutes it returns to the normal operation.]
HP-A control
• If the pressure switch (63H
or stopped (for the operations of patterns C
frequency, the frequency is dropped futher by 10 Hz. (Minimum frequency is specified at the partial load of 35 Hz.)
• Operation returns to the normal mode after operating with the frequency control at off
Note (1): If the high pressure A control is released,the frequency is raised by 5 Hz and retained at the level for 3 minutes. The
frequency is then raised by 5 Hz at 3-minute intervals till it returns to the normal operation.
ON
OFF
OFF
ON
OFF
OFF
OFF
(See page 1075) on the outdoor unit control circuit board to ON, and the outdoor fan of a standing unit
OFF
5°C
(2) (full load conversion frequency:23Hz to 35Hz) is selected. (20V
) is actuated, the outdoor blower is opreated in the Hi mode (for the operations of patterns A
2
to E ) and, if it is still actuated 2 minutes after a drop of 10 Hz in the inverter
2 2
ON
OFF
OFF
ON
ON
3°C (Outdoor air temperature)
(1) to expand the capacity control range in the low
F
0 10 20 3035 40 45 50 55 60 70 80 90
2 ) is actuated twice within 45 minutes, the
6 minutes after the 63H
(1)
FDC-HKXR
: OFF, 20V : ON)
U
Hot gas bypass
Ferquency (Hz)
to C
1
having been reset.
2
1039
)
1