Pump Down Procedure (Common To Cooling And Heating); Select The Pump-Down Mode; Stop Operation For All Indoor Units; Remove Refrigerant Shutoff Valve Cap - Panasonic U-16GE2E5 Main Parts Replacement

Pump Down Procedure (Common to Cooling and Heating)

Safety Precautions
Stopping only the indoor unit is extremely dangerous because the engine may suddenly start if the customer
operates a remote control on the indoor unit. When working on internal parts of the outdoor unit, make sure to cut
the power to the outdoor unit at the circuit breaker before starting work. (However, if a system controller or other
centralized control device is being used, an abnormal communications error may be generated. Alternatively,
perform the STOP operation for the outdoor unit.
• Items 1 to 5 below describe the preparation work for the pump-down.

1. Select the pump-down mode.

The following two types of pump-down mode are available. Select the correct mode according for your purpose.
(1) To recover refrigerant to the outdoor unit side
(2) To recover refrigerant to the indoor unit side
* Although the work is in principle the same for each of the modes, some parts differ. Be careful because the
following explanation is for both the cooling mode and heating mode.

2. Stop operation for all indoor units

Turn off remote controllers for all indoor units.
* The test run settings cannot be con gured from the outdoor main board while the indoor unit is being operated
(remote controller is on).
* Cooling is not possible during the pump-down work and until recovery is complete after the work is nished, so
make sure the customer is aware of this before you begin work.

3. Remove refrigerant shutoff valve cap

Remove the cap from each of the refrigerant and oil tube shutoff valves (Figure 1).
• Refrigerant gas pipe
• Refrigerant liquid tube

4. Attach the gauge manifold

Attach the pressure gauge (gauge manifold) for monitoring the refrigerant pressure in order to determine when the
pump-down is complete.
The location to attach the gauge differs for each model and depends on the pump-down mode.
(1) For standard devices and W-multi:
• Cooling pump-down
• Heating pump-down
Refrigerant liquid
shutoff valve
Closed valve
cap
Refrigerant pipe service port (Figure 1)
Refrigerant low pressure service port (Figure 2)
Refrigerant gas
shutoff valve
Service port
(gauge installation)
Figure 1
Cooling pump-down
Heating pump-down
69
Service port
(gauge installation)
Four-way valve
Figure 2