119
Heating
①
Starting condition
Ps
<
0.15MPa
②
Controls
By SV1control/Compressor frequency conrtol, make low pressure value always higher than the rated value.
<
0.15MPa (-32°C)
SV1:ON
Ps0.15MPa
PID control
≥0.2MPa(-27°C) *2
Start again after 5 minutes
System protection
stop
<
0.05MPa *1
<
0.03MPa
Error, system stop
Error, system stop
Normal operation
*1: When last for 5 minutes system will stop for protection
*2: Minimum power on time for SV1 is 2 minutes or Ps
>
0.25MPa in 2 minutes
③
Quit condition
Ps≥0.20MPa
18.6 SV1 control
Pd
≥3.8MPa, SV1 open; Pd
<
3.5MPa, SV1 close.
Minimum open time for SV1 is 1 minute, or Pd
≤34kgf in 1 minute
18.7 Outdoor LEV control
Cooling super heat control
Control by indoor Tho-Thi target super heat value, and also consider modification value
△
SH when discharge
temp too high.
Modification target SH= Target SH (Tho-Thi)+
△
SH, -12°C
≤SH≤2
°C
Heating super heat control
Adjust target exhaust superheat