Auto Mode Function; Forced Operation Function; Action Of 4-Way Valve; Function - Midea MSY-09HRDN1-QC8 Service Manual

The machine will quit from the rating capacity test mode if running for 5 hours or changing fan
speed or setting temperature.
8.7.9 Turbo function in heating mode. (press the "TURBO" button on remote controller)
Elevate current frequency (excluding F8) to a higher grade. If indoor fan is in low speed or pause
caused by defrosting or anti-cold-wind function, frequency of compressor will not be elevated one
grade until these limit has been released.
Indoor fan changes to turbo speed and anti-cold-wind function is valid.

8.8 Auto mode function

8.8.1 This mode can be chosen with remote controller and the setting temperature can be
changed between 17~30℃.
In auto mode, the machine will choose cooling, heating or fan-only mode according to ΔT (ΔT
=T1-Ts).
ΔT=T1-Ts
ΔT＞1℃
-1≤ΔT≤1℃
ΔT＜-1℃
8.8.2 Indoor fan will choose auto speed of relevant mode.
8.8.3 If the machine switches mode between heating and cooling, compressor will keep stopping
for 15 minutes and then rechoose mode according to ΔT.
8.8.4 If the setting temperature is modified, the machine will rechoose running function.

8.9 Forced operation function

8.9.1 Forced cooling and auto function can be carried out through a touch button. In these two
modes, the machine can be changed by remote controller to any other mode at any moment.
8.9.2 When the machine is off, pressing the touch button will carry the machine to forced auto
mode, after this, if pressing the button once again within 5 seconds, the machine will turn into forced
cooling mode. In forced auto, forced cooling or any other operation mode, pressing touch button
will turn off the machine. In forced operation, remote control is available.
8.9.3 In forced operation mode, all general protections are available.
8.9.4 In forced cooling mode, after running for 30 minutes with compressor frequency F2 and
breeze indoor fan speed, the machine will turn to normal auto mode in which setting temperature is
24℃.
8.9.5 The action of forced auto mode is the same as normal auto mode which temperature is 24℃.

8.10 Action of 4-way valve

For MSY-09HRDN1-QC2 and MSY-12HRDN1-QC2
In cooling, drying, fan-only, or turning off mode, 4-way valve is off, while in heating mode 4-way
valve is on. If the machine changes operation mode from heating mode to some other mode,
4-way valve will be delayed off 2 minutes after compressor stop. For defrosting, please refer to the
passage "defrosting mode".
For MSY-09HRDN1-QC2 and MSY-12HRDN1-QC2 and MSY-18HRDN1-QC2
In heating, fan-only, standby or turning off mode, 4-way valve is off, while in cooling\drying and
Running mode
Cooling
Fan-only
Heating
30