Panasonic U-4LE2E5 Service Manual & Test Run Service Manual page 82

7. Pumping Out Refrigerant from Outdoor Unit
(7) Short-circuit the AP pin on the outdoor unit control PCB. Then turn ON the outdoor unit power.
CAUTION
(8) Open both Hi- and Lo-side valves on the manifold gauge valves, and recover the refrigerant remaining in the
outdoor unit. Then measure the amount of recovered refrigerant.
NOTE
To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.
7-2. If Remote Controller is Not Available 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 the
3
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) Short-circuit the MODE pin ("HEAT" side) on the outdoor unit control PCB.
(3) Short-circuit the CHK pin to start operation, leave the unit running for a while. Touch the gas tubing with fingers
to determine whether the unit is running in heating.
When the AP pin is short-circuited and the power is turned ON, all solenoid valves
in the outdoor unit are forced open, allowing the refrigerant to be recovered from all
tubes which are separated by solenoid valves. If this work is not performed, it will not
be possible to recover all of the refrigerant at the refrigerant recovery device. Be sure
to perform this step.
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.
Outdoor Unit Repair Procedures
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Mini VRF SYSTEM