Midea MSR1-24HRDN1-QC2W Service Manual page 22

When the machine is running and ∆T(=room temp. – setting temp.) changes, the frequency of compressor will
rise or descend a grade (7 minutes after starting).
After starting, if ∆T stays in a zone for 3 minutes, the frequency will change as follow:
Zone A : Current frequency rise a grade till the maximum grade F8.
Zone B: Keep the current frequency of compressor.
Zone C: Descend the current frequency of compressor until F1.
Zone D: Compressor stops after running as the minimum frequency F1 for 60 minutes or ∆T is less than -2℃.
8.5.2 Indoor heat exchanger anti-freezing function.
If T2 is lower than 0℃, the compressor stops and resumes when T2>5℃.
8.5.3 Outdoor unit current control in cooling mode(refer to the parameter table)
8.5.4 Rating capacity test function
1) Set the indoor unit with remote controller as: high fan, 17℃ in cooling mode, then press "TURBO" button on
controller 6 times or more within 10 seconds(make sure indoor unit receives these signals), the machine
will turn into rating capacity test mode, the buzzer will make a "di" sound for 2 seconds continuously. Also,
indoor fan will change to rating speed, the frequency of compressor will be fixed as rating value. Any
condition of above is not satisfied, the machine can not be turned into rating capacity test mode.
2) The machine will quit from the rating capacity test mode if running for 5 hours or changing fan speed or
setting temperature.
8.5.5 Turbo function(press the "TURBO" button on remote controller)
1) Elevate current frequency to a higher grade.
2) Indoor fan turns to turbo speed.
3) After running for 30 minutes the machine will turn back to previous setting mode.
8.5.6 Indoor fan operation rule.
1) In cooling mode, indoor fan runs all the time and the speed can be selected as high,
1.5
1.0
0.5
-0.5
-1.0
I3COOL
I2COOL
I1COOL
A
B
C
D
comp. pause
freq. descends if curr. rises;
freq. remains if curr. descends
running normally
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