Panasonic Urban Multi MX1R Series Service Manual page 49

Function
1.5.3 Pump Down Start
If the compressor stops running with refrigerant still remaining in the accumulator, in order to prevent wet
operation at the next compressor starting, it will perform pump down start with a completely dry
accumulator, then it will operate normally.
Pump down start should be performed if the unit is in any of the conditions given below when pressure
equalizing control has been completed before start.
If R3T (R3-1T) is less than 95°C and the unit is in any of the following conditions.
‹ Within 10 minutes of the compressor starting
‹ Defrosting or during oil return
‹ Within 20 minutes of completion of defrost or oil return
‹ Outdoor air temperature is less than -5°C (MX1 Series)
‹ Outdoor air temperature (R1T) < 0ºC (ME1 Series)
‹ Oil temperature (R5T) < Te + 10ºC (ME1 Series)
Operation During
Pump Down Start
MX1 Series
Compressor
Outdoor unit EV
Outdoor unit fan
Y2S
Y3S, Y4S
Note 1. Note 1: 30Hz (30Hz+OFF) for products produced after Aug. '99.
2. ∗ Note 2 : When heating, low pressure < 1.5 kg/cm² (0.147MPa) → running frequency 54Hz (54Hz +
‹ Y2S: Hot gas bypass solenoid valve
‹ Y3S: Injection solenoid valve
ME1 Series
Compressor
Outdoor unit EV
Outdoor unit fan
Y2S
Y3S
‹ Y2S: Hot gas bypass solenoid valve
‹ Y3S: Injection solenoid valve
28
Te : Low pressure equivalent saturated temperature
← 11 min. 30 sec. →
1 min.
42Hz
(42Hz+OFF)
0 pulses
H tap (H+ON)
ON
ON
OFF)
Low pressure > 1.7 kg/cm² (0.167MPa) [30 sec. continuous] → release
← 11 min. 30 sec. →
1 min.
42Hz+OFF
0 pulses
H tap (H+ON)
ON
ON
5 min. 30 sec.
42Hz
(42Hz+OFF) (42Hz+OFF) Note 1
0 pulses
H tap (H+ON) H tap (H+ON)
ON ON
ON/OFF
(Td protection control) (Td protection control)
5 min. 30 sec.
42Hz+OFF 30Hz+OFF
0 pulses
H tap (H+ON) H tap (H+ON)
ON ON
ON/OFF
(Td protection control) (Td protection control)
Function Urban Multi "MX1, ME1 Series" Using R-22
PACD011001C2
30 sec. 4 min. 30 sec.
42Hz 30~106 Hz+OFF
PI control ∗ Note 2
0 pulses SH control (Initial
opening 150 pulses)
H tap (H+ON)
OFF ON/OFF
(LP protection control)
ON/OFF ON/OFF
(Td protection control)
30 sec. 4 min. 30 sec.
116Hz+OFF
0 pulses 150 pulses
H tap (H+ON)
OFF ON/OFF
(LP protection control)
ON/OFF ON/OFF
(Td protection control)