Panasonic CU-YL28HBE5 Service Manual page 36

• If a drain pipe needs to be installed, insert the accessory drain elbow into the mounting hole at the bottom of the outdoor unit, and
connect a hose with an inside diameter of 15mm to this drain elbow.
(The hose is not supplied.)
If using the drain elbow, install the outdoor unit on a base which is at least 5cm high.
NOTE
In cold regions (where the outdoor air temperature can drop to 0°C or below continuously for 2-3 days), the drain water may freeze,
and this may prevent the fan from operating. Do not use the drain elbow in such cases.
10.1.5. Notes On Reuse Of Existing Refrigerant Piping
Observe the followings when reusing the existing refrigerant piping.
Inadequate refrigerant piping could result in failure.
• In the circumstances listed below, do not reuse any refrigerant piping. Instead, make sure to install a new piping.
(Reuse is not allowed.)
- Heat insulation is not provided for either liquid-side or gas-side piping or both.
- The existing refrigerant pipe has been left in an open condition.
- The size of the existing refrigerant piping does not meet the applicable size requirement. (Applicable piping size is as
indicated in the table below.)
- The length of the existing refrigerant piping is not within the range of allowable piping length. (Allowable length range is as
indicated in the table below.)
- Branch pipe is used for twin type or branch piping is run on indoor side.
• In the circumstances listed below, do not reuse the refrigerant piping as it is but wash it thoroughly before reusing it.
- Pump down operation cannot be performed for the existing air conditioner.
- The compressor has a failure history.
- Oil is discolored.
- The existing air conditioner is gas/oil heat pump type.
- Refrigerant oil used for the existing air conditioner is other than "ester oil, ethereal oil, ATMOS, SUNISO or H.A.B".
• 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.
10.1.6. Refrigerant Piping Size And Allowable Piping Length
1. Refrigerant piping size
Outdoor unit capacity
YL24, YL28 type
Outdoor unit capacity
YL24, YL28 type
• In case of new installation, make sure to use standard piping size.
• In case of reuse of existing piping, the size must be within the range of refrigerant piping size combination as specified in the
above table.
Liquid-side applicable piping size (mm)
1 size down
ø6.35 x t0.8
Gas-side applicable piping size (mm)
Standard
ø15.88 x t0.8
36
Standard
ø9.52 x t0.8
1 size up
—
1 size up
ø12.7 x t0.8