Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 139

(8) Determining the operating mode
The cooling and heating operating modes are the remote control switch mode that have been previously determined.
If a mode differing from these is selected after this, the selected mode will appear in the display of the remote control, but only the
fan will operate.
First operation
Example
Selected Mode Remote Control Display
1 Cooling
Cooling
2
Cooling Cooling
3
Heating
Heating
4
Heating Heating
Example of operating pattern
Cooling
switch
A unit
ON
Heating
B unit switch
ON
Operation Operation
(9) Control and protection functions
(a) Control during start of compressor operation
1) Soft start
The inverter starts from 4 Hz when starting from the stop mode to control the starting current.
2) Start of protection for compressor
When the inverter decision frequency is 36 Hz or more, compressor protection starts.
1 Start of protection I (The first time after the power is turned on and when starting after having been stopped for 6
hours or more.)
After the compressor has been started, the frequency of the outdoor unit is maintained at a maximum of 52 Hz for 5
minutes, after which transition is made to the decision frequency.
2 Start of protection II (Other than item 1 )
After the compressor has been started, the frequency of the outdoor unit is maintained at 40 Hz for 1 minute and 45
seconds, after which transition is made to the decision frequency.
3 Start of protection III (The first time after the power is turned on and when starting when the total power-on time is
less than 6 hours.)
After the compressor has been started, it is operated at 40 Hz for 30 seconds. Then for the next 10 minutes it
increases at a rate of 2 Hz every 30 seconds to the upper limit frequency of the outdoor unit. For the next 4 minutes,
the increase is 2 Hz every 15 seconds.
3) Delay of compressor start
If the compressor (inverter) is stopped by the operation of the cooling or heating thermostat, the operation switch on the
remote controller or an abnormality, it cannot be restarted for 3 minutes.
However, turning on the power disables the 3-minute timer.
(b) Heating overload protection control
When the outdoor units are operating at a frequency other than 0 Hz and the outdoor air temperature is 17°C or more for 30
continuous seconds, the heating overload protection control (current safe control) operates. However, when one unit is
operating, the outdoor frequency is forced to 16 Hz. Recovery is when the outdoor air temperature is 16°C or less.
(c) Cooling overload protection control
When the outdoor units are operating at a frequency other than 0 Hz and the outdoor air temperature is 39°C or more for 3
continuous minutes, the fan speed of the outdoor unit is increased 1 speed and the current safe control operates. Recovery is
when the outdoor air temperature is 38°C or less.
Second operation
Operation Selected Mode Remote Control Display
Cooling Heating
Cooling Fan
Heating Cooling
Heating Fan
Cooling
Cooling
Fan
switch
ON
Operation Operation
Notes
Operation
Heating Fan (1)
• Different mode
Fan Fan
is only fan
Cooling Fan
operation.
Fan Fan
Heating
switch Fan Heating
ON
Heating
Cooling
switch
Operation
SCM-HG (4 room)
Note (1) If the display shows heat-
ing and the opera-tion is
fan, Hot Keep will op-
erate.
Heating
ON
Note (1) [ ] indicates current operation.
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