Panasonic S-45PU1E5 Technical Data & Service Manual page 323

Leak Test
(1) With the service valves on the outdoor unit closed, remove the 6.35 mm flare nut and its bonnet on the gas tube
service valve. (Save for reuse.)
(2) Attach a manifold valve (with pressure gauges) and dry nitrogen gas cylinder to this service port with charge
hoses.
CAUTION
Use a manifold valve for air purging. If it is not available, use a stop valve for this purpose.
The "Hi" knob of the manifold valve must always be kept closed.
(3) Pressurize the system up to 4.15 MPa {42 kgf/cm
when the gauge reading reaches 4.15 MPa {42 kgf/cm
Then, test for leaks with liquid soap.
CAUTION
To avoid nitrogen entering the 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 a 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.
Evacuation
Be sure to use a vacuum pump that includes a function for prevention of back-flow, in order to prevent back-flow of
ump oil into the unit tubing when the pump is stopped.
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. Confirm 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.
Confirm that the gauge pressure is under –101 kPa
{–755 mmHg, 5 Torr} after 4 to 5 minutes of vacuum pump
operation.
CAUTION
Use a cylinder specifically designed for use with R410A.
2 G} with dry nitrogen gas and close the cylinder valve
G}.
2
Manifold valve
Lo
Pressure
gauge
Gas tube
Liquid tube
1-313
Hi
Vacuum pump
Open
Close
Outdoor unit
Close
1