Functions and control
18 Domestic air conditioner
The EEV opening will increase if SH (superheat degree) >0 while decrease if SH<0.
Adjust frequency:
If |SH|=0, 60s/ 1 step
If |SH|
ı
3,and
Ƹ
SH=0, 10s/ 1 step.
If 3
ı
|SH|
ı
0, 30s/ 1 step.
Ƹ
SH= current SH- last SH
SH= Ts (suction temp)-Tc1 (indoor coil temp)-Tsh (fixed data, depend on different models, -1~2)
7.1.4 Four way control
For the details of defrosting four-way valve control, see the defrosting process.
Four way working in other ways:
Under the mode of heating, open the four-way valve, when the compressor is not started or
changed to non-heating mode, make sure the compressor is stoped for 2 minutes, and then close the
four-way valve.
7.1.5 Protection function
7.1.5.1 TTC high temperature-preventing protection
Once the machine is started, it can run TTC(air-blowing temp) overheating protection of
air-blowing, but air-blowing sensor malfunction must alarm after 4 minutes during which the
compressor is started (during the course of self-detection, there’s no such limitation)
Sensor detection methods: 100 times (one cycle of procedure run is one time, and about 5ms,
detection method for each time: continuously sampling for 8 times, then order them and take the mean
value of the middle 2 values), take the mean value.
TTC
˄ć˅
18K
˄
24K
˅
Abnormal stop
110
˄
110
˅
Decreasing the frequency rapidly
˄
1HZ/second
˅
107(105)
Decreasing the frequency slowly (1HZ/10seconds)
102(100)
The frequency doesn’t change.
98(98)
Increasing the frequency (1HZ/10second)
93(93)
Increasing the frequency
˄
1HZ/1second
˅
TTC>=110
ć
lasts for 20 seconds. Overheating protection of air-blowing, alarm malfunction to the
indoor, others don’t last.
7.1.5.2 TC high temperature-preventing control of the indoor heating unit
˖
Tpg_indoor is the highest value of the effective indoor unit (start it and it is in accord with the
running state). TC=indoor coil temp.
The indoor heat exchanger sensor tests the temperature of the indoor heat exchanger. If the
temperature is higher than 63
ć
, decrease the rotate speed of the compressor and do the high
temperature-preventing protection of the indoor heat exchanger; if the temperature of the indoor heat
exchanger is lower than 45
ć
, recover to the normal control.
Summary of Contents for 1U68REMFRA
Page 11: ...Pinping diagrams Domestic air conditioner 4ˊPiping diagrams 9 EEV EEV ...
Page 12: ...Operation range 10 Domestic air conditioner 5 Operation range 10 0 21 27 35 20 40 60 43 20 40 ...
Page 39: ...Service diagnosis 37 Domestic air conditioner ...
Page 46: ...Service diagnosis 44 Domestic air conditioner ...
Page 58: ...58 Do C omestic air ircuit Diagra conditioner ams r 12 2 Module board circuit diagram ...
Page 59: ...57 Do C omestic air ircuit Diagra conditioner ams r ...
