Panasonic Urban Multi MX1R Series Service Manual page 463

Outline of Control
3.1.15 Crankcase Heater Control
Controls the crankcase heater to prevent refrigerant from remaining in the inverter compressor.
Note: STD compressor crankcase heater is controlled previous way. (ON/OFF by magnetic switch)
3.1.16 Gas Shortage Warning
Generates a warning when an excessive gas shortage occurs. This function generates an alarm only, and
does not stop operation.
• In cooling mode
· Lp < 0.10MPa (-21.6°C)
· Lp ≥ 0.10MPa (-21.6°C)
• In heating mode
OR
442
Crank case
heater OFF
30 continuous minutes → Outputs gas shortage warning [U0].
→ Cancels gas shortage warning.
SH1 (Evaporator1 outlet
superheat degree) > 20°C
EV1 = 2000 pls (full open)
SH2 (Evaporator2 outlet
superheat degree) > 20°C
&
EV2 = 2000 pls (full open)
SH3 (Evaporator3 outlet
superheat degree) > 20°C
EV3 = 2000 pls (full open)
SH1 (Evaporator1 outlet
superheat degree) ≤ 20°C
EV1 < 2000 pls (full open)
SH2 (Evaporator2 outlet
superheat degree) ≤ 20°C
EV2 < 2000 pls (full open)
SH3 (Evaporator3 outlet
superheat degree) ≤ 20°C
EV3 < 2000 pls (full open)
• Outdoor air temp. < 27 ˚C
• Compressor stop during
&
the magnet contactor of
OR
INV compressor ON
• The magnet contactor of
INV compressor OFF
• Outdoor air temp. > 30˚C
Left conditions
→ Outputs gas shortage warning [U0].
remain for 60
continuous minutes
→ Cancels gas shortage warning.
Function UM Combination "MA1R Series" Using R-407C
PACD011001C2
Crank case heater
ON
(V0833)