Pumping Out Refrigerant From Outdoor Unit - Panasonic U-10MF1E8 Service Manual

9. Pumping Out Refrigerant from Outdoor Unit

Required equipment and tools: Jumper wire with clips, adjustable wrench, set of manifold gauge valves, refrigerant
This work is performed in order to collect the refrigerant from an outdoor unit where repairs (other than compressor
replacement) will be performed into other outdoor units and indoor units, and the refrigerant tubing.
9-1. If Remote Controller (CZ-RTC2) is Used for Maintenance of Outdoor Unit
(1) Refer to "4. Backup Operation" and perform backup operation.
(2) Connect the manifold gauge valves at the Lo side to the low-pressure outlet port of the outdoor unit to be
repaired. Also connect the refrigerant recovery cylinder to any one of the normal outdoor units at the liquid
line service port (Schrader-type push-to-release valve). Perform the connection work quickly so that no air is
allowed to enter. (Fig. 18)
* Connecting the refrigerant recovery cylinder is done to prevent pressure from rising excessively during
2
backup operation by recovering the refrigerant from the outdoor unit to be repaired.
(Measure the weight of the refrigerant and cylinder itself beforehand and provide sufficient safety measures,
such as installing a high-pressure cutout in the circuit.)
CAUTION
(3) Connect the outdoor unit maintenance remote controller to the RC connector (CN006) (3P) (BLU) on the
outdoor unit control PCB of the outdoor unit to be repaired. Then start a test run of all units. (Press and hold the
(CHECK) button for 4 seconds.)
(4) Press the
CAUTION
(5) Use the outdoor unit maintenance remote controller to check the operating status of the indoor units. Check
that all units are operating in Heating mode. For details concerning operation of the outdoor unit maintenance
remote controller, refer to the "Outdoor unit maintenance remote controller" item.
CAUTION
(6) Close the suction tube and balance tube on the outdoor unit to be repaired. Then slowly close the liquid tube
service valve.
(7) When the low pressure at the outdoor unit to be repaired reaches 0.5 MPa or below, press the ON/OFF
button on the outdoor unit maintenance remote controller to stop all the units. Then immediately fully close the
discharge tube valve on that outdoor unit.
CAUTION
(8) Connect the high-pressure gauge side of the manifold gauge to the high-pressure outlet port on the outdoor
unit to be repaired, and connect the manifold gauge to the refrigerant recovery device. Be sure that no air
enters the tubing at this time.
recovery unit, pre-purged refrigerant cylinder for recovery, flat-head screwdriver,
and outdoor unit maintenance remote controller.
The hoses may be subject to internal pressure from the refrigerant inside the
outdoor unit. Check that the manifold gauge valves are fully closed beforehand.
A Schrader-type push-to-release valve is provided at each connection port.
(MODE) button and change to heating operation.
Even if the mode that is originally displayed is "Heat," be sure to press the
(MODE) button once or more to change to heating operation. (Pressing the
(MODE) button ensures that heating/cooling operation is not mixed and that all
units are operating in either Heating or Cooling mode.)
With the 3-way valve, it is difficult to determine whether operation is heating or
cooling by touching the tubing.
While closing the valves, the rise in discharge temperature or another factor may
cause a protective device to activate, stopping the operation of the outdoor unit. If
this occurs, immediately fully close the discharge tube valve on the outdoor unit to be
repaired.
Outdoor Unit Repair Procedures
2 - 20
3-WAY SYSTEM