Panasonic R410A service manual Specifications, Evacuation, Use a cylinder specifically, Fig

(3)Pressurize the system up to 4.15 MPa

(42 kgf/cm2G) with dry nitrogen gas and close the cylinder valve when the gauge reading reaches 4.15 MPa (42 kgf/cm2G). Then, test for leaks with liquid soap.

To avoid nitrogen entering the CAUTION refrigerant system in a liquid

state, the top of the cylinder must be higher than the bottom when you pressurize the system. Usually, the cylinder is used in a vertical standing position.

(4)Do a leak test of all joints of the tubing (both indoor and outdoor) and both gas and liquid service valves. Bubbles indicate a leak. Wipe off the soap with a clean cloth after the leak test.

(5)After the system is found to be free of leaks, relieve the nitrogen pressure by loosening the charge hose connector at the nitrogen cylinder. When the system pressure is reduced to normal, disconnect the hose from the cylinder.

2. Evacuation

Be sure to use a vacuum pump that includes a function for prevention of back-flow, in order to prevent back-flow of pump oil into the unit tubing when the pump is stopped.

Pressure gauge

Gas tube

Liquid tube

1. Specifications

Manifold valve

Lo Hi

Vacuum pump

Open

1

Close

Outdoor unit

Close

Perform vacuuming of the indoor unit and tubing. Connect the vacuum pump to the gas tube valve and apply vacuum at a pressure of –101kPa ( –755 mmHg, 5 Torr) or below.

Continue vacuum application for a minimum of 1 hour after the pressure reaches –101kPa ( –755 mmHg, 5 Torr).

(1)Attach the charge hose end described in the preceding steps to the vacuum pump to evacuate the tubing and indoor unit. Confi rm that the “Lo” knob of the manifold valve is open. Then, run the vacuum pump.

(2)When the desired vacuum is reached, close the “Lo” knob of the manifold valve and turn off the vacuum pump. Confi rm that the gauge pressure is under –101kPa ( –755 mmHg, 5 Torr) after 4 to 5 minutes of vacuum pump operation.

CAUTION	Use a cylinder specifically
	designed for use with R410A.

Fig. 1-125

1-123