Pump Down Residual Operation - Panasonic Urban Multi MX1R Series Service Manual

PACD011001C2
1.12

Pump Down Residual Operation

1.12.1 MX1 Series
If refrigerant is remaining in the accumulator when the compressor starts, liquid refrigerant is sucked into
the compressor, diluting the refrigerant machine oil and reducing the lubricating performance. To prevent
this, the pump-down operation discharges refrigerant from the low pressure side when the unit is not in
operation.
Residual operation may be carried out for 10 minutes under the following conditions when heating.
1. When outdoor temperature (R1T) is ≥ -5°C and inverter discharge pipe temperature (R3-1T) < 95ºC,
2. When the thermostat is ON during residual operation, residual operation is not carried out if the total of
Thermostat
Compressor and
outdoor unit fan
3. When outdoor temperature (R1T) < -5°C and a stop command is received from the thermostat sensor,
Function Urban Multi "MX1, ME1 Series" Using R-22
and a OFF by thermostat command is received with the compressor's continuous operation time being
10 minutes or less, residual operation is carried out for a maximum of 10 minutes.
Discharge pipe thermistor (R3-1T) on inverter side: 95°C or lower
Outside air temperature thermistor (R1T) < 0°C
When compressor continuous operating time is less than 10 minutes and thermostat is OFF, or
&
when stop command is received from remote controller
OR
Within 20 minutes after defrost or oil return operation
T0 (oil temperature) ≤ Te+10
Max. 10 min.
ON
Thermostat
OFF
ON
Compressor and
outdoor unit fan
OFF
1+2+3 is 10 minutes or more.
Max. 10 min.
ON
OFF
1
ON
OFF
etc., residual operation is carried out for 10 minutes without fail. (Operation may however stop for
discharge pipe or high/low pressure safety.)
Residual operation for 10 min.
Max. 10 min.
Residual
operation
2
Residual operation not carried out
if 1 + 2 + 3 is 10 minutes or more.
Operation may stop during the 10 minutes
residual operation due to protection discharge,
high/low pressure, etc.
3
Thermostat
ON
Function
(VL006)
(VL007)
39