Panasonic CS/CU-HU12ZKY Series Operating & Installation Instructions Manual page 26

In Case of Reusing Existing Refrigerant Piping
Observe the followings to decide reusing the existing refrigerant piping.
Poor refrigerant piping could result in product failure.
• In the circumstances listed below, do not reuse any refrigerant piping. Instead, make sure to install a new piping.
Heat insulation is not provided for either liquid-side or gas-side piping or both.
O
The existing refrigerant pipe has been left in an open condition.
O
The diameter and thickness of the existing refrigerant piping does not meet the requirement.
O
The piping length and elevation does not meet the requirement.
O
Perform proper pump down before reuse piping.
• In the circumstances listed below, clean it thoroughly before reuse.
Pump down operation cannot be performed for the existing air-conditioner.
O
The compressor has a failure history.
O
Oil color is darken. ( ASTM 4.0 and above ).
O
The existing air-conditioner is gas/oil heat pump type.
O
• Do not reuse the flare to prevent gas leak. Make sure to install a new flare.
• If there is a welded part on the existing refrigerant piping, conduct a gas leak check on the welded part.
• Replace deteriorated heat insulating material with a new one.
Heat insulating material is required for both liquid-side and gas-side piping.
Proper Pump Down Method
Operate air
conditioner at
cooling mode for
10 ~ 15 minutes.
Most Important Process
Purpose: To make the oil
& refrigerant mix together.
They are in separated
condition when
air conditioner
is stopped.
In case pump down cannot be done, please e flush the piping using R32 refrigerant.
Check Items
Is there any gas leakage at fl are nut connections?
Has the heat insulation been carried out at fl are nut
connection?
Is the connection cable being fi xed to terminal board
fi rmly?
Is the connection cable being clamped fi rmly?
Is the drainage ok?
(Refer to "Check the drainage" section)
Is the earth wire connection properly done?
26
After 10 ~ 15 minutes of pre
operation, close 2 way valve.
After 3 minutes, close 3 way
valve.
Mixed refrigerant &
oil will be collected
into outdoor unit.
Must do re- - flare of pipes before connecting to units.
Take out air
conditioner unit.
Only very small
amount of oil remain
inside piping, which
is acceptable.
Is the indoor unit properly hooked to the installation plate?
Is the power supply voltage complied with rated value?
Is there any abnormal sound?
Is the cooling/heating operation normal?
Is the thermostat operation normal?
Is the remote control's LCD operation normal?
Is the Ag Clean Filter installed?
+
Is the PM 0.1 Filter installed?
Install New
Refrigerant air
conditioner.