Midea U2MRS-12, Service Manual

Page: 106 / 159

Electrical Control Function
112 Electrical Control System
For Compact cassette(12K) 、 A5(12K)
In cooling mode, indoor fan runs all the time and the speed can be selected as high, medium, low, auto and
silent.
The auto fan:
3.5
3.0
High
Low
1.0
Medium
1.5
For other models:
5.0
4.0
High
Low
2.0
Medium
3.0
1.3.2.4 Evaporator low temperature T2 protection.
For 12K units ：
---T2<0
℃
, the compressor will stop and restart when T2
>=
5
℃
.
---0
℃ ≦
T2<4
℃
, the compressor frequency will be limited and decreased to the lower level
---4
℃
≤ T2<7
℃
, the compressor will keep the current frequency.
---T2>7
℃
, the compressor frequency will not be limited.
For other units: When T2<2 ℃ and lasts for 3 minutes, the indoor has no capacity demand and resume till T2
≥
7
℃
.
1.3.2.5 Condenser high temperature T3 protection
For 12K units :
---55
℃
<T3<60
℃
, the compressor frequency will decrease to the lower level until to F1 and then runs at F1.If
T3<55 ℃ , the compressor will keep running at the current frequency.
---T3<52 ℃ , the compressor will not limit the frequency and resume to the former frequency.
---T3>60
℃
for 5 seconds, the compressor will stop until T3<52
℃
.
For other units: When T3 ≥ 65
℃
for 3 seconds, the compressor will shut off. When T3
＜
52,the compressor
will restart.