Midea MPPD-12CRN1-BH9 Service Manual page 10

The ION/TIMER functions are valid at the heating mode.
3.4.6 Heating mode function requirement(for Heat Pump)
TS range is 62
℉
T1≤TS+41 5
℉(
T1﹥TS+42.8
℉(
5
T1﹤41
℉( ℃), heat pump mode is invalid; Water pump,fan motor, compressor
and shaded pole motor stop operation;
T1≥42.8 6
℉( ℃) , heat pump mode resume.
When four-way valve open(on non-defrost situation), shaded pole motor is always off.
When compressor operates, outdoor fan motor is at high speed.
When compressor stops, outdoor fan motor stops for a delay of 30seconds.
If unit changes for other operation modes, four-way valve closes for a delay of
2 minutes than compressor.
When compressor is on, T2
≥86 30
When T2 ℉(
motor is on operation for 3 minutes at first, then according to the temperture T2 to
choose speed.
≥100.4 38
If T2 ℉(
When compressor stops, indoor fan motor also stops, the unit can be set at high/mid/
low/auto speed. Indoor fan motor will be off for a delay of 20 seconds becaues of
compressor being off by change of temperature or power off.
Water pump control:
a) At Heat pump mode, when LED displays as P1, or S1 disconnets continuously for 5
seconds, water pump starts to drain.
b) If S1 closes continuously over 5 seconds, it means that the water level of chassis is
below to S1. After it lasts working for 100 seconds, it will stop.
c) If unit changes for other operation mode or power off, water pump closes immidiately.
Defrosting function:
1. Defrosting condition: T3
2. Defrosting action:
a) Compressor operates, four-way valve and indoor/outdoor fan are off.
b) When time is over 7 minutes or temperatrue is over 40℃,the outdoor fan is on and
continuosely working till the defrosting over.
3. Defrosting over: Defrosting time is up to 10 minutes; T3
4. Outdoor fan works, and compressor stops. After 35 seconds, four-way valve
opens, 3 seconds later, the compressor operates.
~88 ( 17 ~30
℉ ℃
, compressor operates;
℃)
6
, compressor stops;
℃)
﹤86
℉(
℃) or compressor deing on operation for 30 seconds, indoor fan
℃), unit operates at setting speed.
≤35.6
℉(
℃).
30
℃), fan motor stops;
2
℃), and operation time is up to 40 minutes.
≥122 50℃)
℉(
