Insulating The Refrigerant Tubing - Panasonic PAW-500ZDX3N Installation, Use And Maintenance Manual

Energy recovery ventilation unit with dx coil

Table of Contents

3.8 Connecting the Refrigerant Tubing

CAUTIONS DURING BRAzING

Replace air inside the tube with nitrogen gas to prevent copper oxide film from forming during the brazing process. (Oxygen, carbon dioxide

and Freon are not acceptable.)

● Do not allow the tubing to get too hot during brazing.The nitrogen gas inside the tubing may overheat, causing refrigerant system valves to

become damaged. Therefore allow the tubing to cool when brazing.

● Use a reducing valve for the nitrogen cylinder.

● Do not use agents intended to prevent the formation of oxide film. These agents adversely affect the refrigerant and refrigerant oil, and may

cause damage or malfunctions.

TIGhTENING

In the table below are shown the pipes diameter for each unit

Unit

Gas Pipe

Liquid Pipe

For the flare nuts at tubing connections, be sure to use the flare nuts that were supplied with the unit, or else flare nuts for R410A. The refrige-

rant tubing that is used must be of the correct wall thickness as shown in the table below.

ø 6,35 (1/4")

ø 12,7 (1/2)"

Because the pressure is approximately 1.6 times higher than conventional refrigerant pressure, the use of ordinary flare nuts or thin-walled

tubes may result in tube rupture, injury, or asphyxiation caused by refrigerant leakage.

● In order to prevent damage to the flare caused by overtightening of the flare nuts, use the table above as a guide when tightening.

● When tightening the flare nut on the liquid tube, use an adjustable wrench with a nominal handle length of 200 mm.