Panasonic Urban Multi MX1R Series Service Manual page 461

Outline of Control
3.1.13 Discharge Pipe Temperature Control
Controls the liquid injection and operating frequency to prevent abnormal increase of discharge pipe
temperature and compressor internal temperature.
„ Opens SVTi (Y3S) (solenoid valve for inverter compressor liquid injection) for 3 minutes after
Liquid Injection
Control (Inverter
Compressor)
[Cooling]
DSHi: Inverter compressor discharge pipe superheated degree
Tdi: Inverter compressor discharge pipe temperature (Th3-1)
[Heating]
[Preparing Oil return and defrosting operation (1 min before operation start)]
[Oil return operation/defrosting operation]
„ SVTi (Y3S) is OFF at any case when inverter compressor stops.
Liquid Injection
[In cooling operation]
Control (STD
Compressor)
DSHs: STD compressor discharge pipe superheated degree
Tds1, 2 : STD compressor discharge pipe temperature (Th3-2)
[In heating operation]
440
software startup.
Normal operation
OR
&
= Tdi (Th3-1) - (HP equivalent saturation temperature)
• Tdi≥100˚C
• LP<0.05MPa
OR
• (HP+0.10) / (LP+0.10)>8
Normal operation
• Tdi<90˚C
• LP>0.07MPa
&
• 2 min elapsed
Preparing oil return
and defrosting
DSHs1, DSHs2≥40˚C
Normal operation
DSHs1, DSHs2<15˚C
= Tds1, 2 (Th3-2) - (HP equivalent saturation temperature)
• Tds1, Tds2≥100˚C
• LP<0.05MPa
OR
• (HP+0.10) / (LP+0.10)>8
Normal operation
• Tds1, Tds2<90˚C
&
• LP<0.07MPa
DSHi≥40˚C
DSHi<15˚C
DSHi<25˚C
10min elapsed
DSHi≥15˚C
SVTs1 (Y4S), SVTs2 (Y6S) : ON
SVTs1 (Y4S), SVTs2 (Y6S) : ON
Function UM Combination "MA1R Series" Using R-407C
SVTi : ON
(V0826)
SVTi : ON
(V0827)
Start oil return
SVTi : ON
& Defrost operation
10 min
(V0829)
2 min
(V0830)
PACD011001C2
(V0828)