Panasonic Urban Multi MX1R Series, Service Manual, Page: 48 / 643

PACD011001C2 Function
Function Urban Multi “MX1, ME1 Series” Using R-22 27
1.5 Safety for Restart
1.5.1 Restart Safety Timer
The compressor will not run for five minutes by making forced thermostat OFF condition in order to prevent
it from being turned on and off in rapid succession, and to equalize pressure in the refrigerant circuit. It
however restarts automatically after five minutes passes if it is in thermostat ON condition. The pressure
equalizing solenoid valve is actuated for 10 minutes (15 minutes for 8 and 10HP heating only) after the
compressor stops in order to equalize pressure.
If 10 minutes or more has elapsed since the compressor was turned off (15 minutes for 8 and 10HP heating
only) , turn the solenoid valve for equalizing pressure on for about 1 minute and equalize the pressure.
When heating, to prevent noise produced by the passing of indoor unit’s refrigerant to equalize pressure
after the compressor stops, fully close the indoor unit’s electronic expansion valve for 5 minutes (10
minutes for 8 and 10HP).
1.5.2 Soft Start
The following control is carried out to protect the compressor and inverter.
1. Operates at low frequency (fixed) for 1 minute after compressor starts. (Prevents liquid refrigerant
backflow)
2. Pressure equalizing and hot gas bypass solenoid valves open and start low load.
Soft Start of
Compressor
Thermostat
Thermostat ON
Thermostat
OFF
Thermostat OFF
Thermostat ON Thermostat ON
Compressor
ON ON ON
OFF OFF
5 minutes
Pressure equalizing
solenoid valve
1 minute
(Soft start) 10 minutes
(15 minutes for
8.10 HP heating only) 1 minute
(Pressure
equalizing) 1 minute
(Soft start)
Indoor unit
electronic expansion
valve (when heating)
Linear control
Fully closed
0 pulses
Linear control
Fully closed
0 pulses
1000 pulses
5 minutes
(10 minutes
for 8 and 10 HP)
240 pulses
1000 pulses
Linear control
OFF OFF
ON ON
OFF
ON
OFF
(VL005)
Compressor frequency
1 minute when started
Time
42Hz
(VG001)
Frequency during soft start
CU-5 42Hz
CU-8·10 42Hz+OFF