Pumping Out Refrigerant From Outdoor Unit - Panasonic U-4LE2E5 Service Manual & Test Run Service Manual

7. Pumping Out Refrigerant from Outdoor Unit

For the method used for additional oil charging after compressor replacement, see the section "6-1. If Refrigerant
Has Already Been Charged to Outdoor Unit."
Required equipment and tools: Jumper wire with clips, adjustable wrench, set of manifold gauge valves for the
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.
7-1. If Remote Controller is Used for Maintenance of Outdoor Unit
(1) Connect the manifold gauge valves at the Lo side to the low-pressure outlet port of the outdoor unit.
Also connect the refrigerant recovery cylinder at the liquid tube service port (Schrader-type push-to-release
valve). Perform the connection work quickly so that no air is allowed to enter them. (Fig. 10)
* Connecting the refrigerant recovery cylinder is done to prevent pressure from rising excessively during 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
(2) Connect the outdoor unit maintenance remote controller to the CN-RC connector (3P) (BLU) on the outdoor
unit control PCB. Then start a test run of all units. (Press and hold the
longer.)
(3) 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, see the section "Outdoor unit maintenance remote controller". It is also possible to check the
operating conditions either in cooling or heating mode by touching the gas tube.
Cooling mode: low temperature (20℃ or lower)
Heating mode: high temperature (60℃ or higher)
CAUTION
(4) Then slowly close the liquid tube service valve.
(5) 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 gas
tube valve on that outdoor unit.
CAUTION
(6) Connect the high-pressure gauge side of the manifold gauge to the high-pressure outlet port on the outdoor
unit, and connect the manifold gauge to the refrigerant recovery device. Be sure that no air enters the tubing at
this time.
refrigerant R410A, refrigerant recovery unit, pre-purged refrigerant cylinder for
recovery, flathead screwdriver, and outdoor unit maintenance remote controller.
The hoses may be subject to internal pressure from the refrigerant inside the out-
door unit. Check that the manifold gauge valves are fully closed beforehand. A
Schrader-type push-to-release valve is provided at each connection port.
The gas tubing becomes hot (60°C or higher) in heating. Be careful so as not to
be burnt when 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 gas tube valve on the outdoor unit to be repaired.
Outdoor Unit Repair Procedures
(CHECK) button for 4 seconds or
3 - 15
Mini VRF SYSTEM
3