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Infiniti Q45 (FY33). Manual - part 462

COMMERCIAL SERVICE TOOL

Tool name

Description

Note

Refrigerant identifier equip-
ment

NT765

Function: Checks refrigerant purity and for
system contamination.

IDX

PRECAUTIONS AND PREPARATION

HFC-134a (R-134a) Service Tools and
Equipment (Cont’d)

HA-13

Precautions for Service Equipment

RECOVERY/RECYCLING EQUIPMENT

Be certain to follow the manufacturers instructions for machine
operation and machine maintenance. Never introduce any refriger-
ant other than that specified into the machine.

ELECTRONIC LEAK DETECTOR

Be certain to follow the manufacturer’s instructions for tester opera-
tion and tester maintenance.

RHA270D

VACUUM PUMP

The lubricant contained inside the vacuum pump is not compatible
with the specified lubricant for HFC-134a (R-134a) A/C systems.
The vent side of the vacuum pump is exposed to atmospheric
pressure. So the vacuum pump lubricant may migrate out of the
pump into the service hose. This is possible when the pump is
switched off after evacuation (vacuuming) and hose is connected
to it.
To prevent this migration, use a manual valve placed near the
hose-to-pump connection, as follows.

Usually vacuum pumps have a manual isolator valve as part
of the pump. Close this valve to isolate the service hose from
the pump.

For pumps without an isolator, use a hose equipped with a
manual shut-off valve near the pump end. Close the valve to
isolate the hose from the pump.

If the hose has an automatic shut off valve, disconnect the
hose from the pump. As long as the hose is connected, the
valve is open and lubricating oil may migrate.

Some one-way valves open when vacuum is applied and close
under a no vacuum condition. Such valves may restrict the pump’s
ability to pull a deep vacuum and are not recommended.

SHA533D

MANIFOLD GAUGE SET

Be certain that the gauge face indicates R-134a or 134a. Be sure
the gauge set has 1/2

″

-16 ACME threaded connections for service

hoses. Confirm the set has been used only with refrigerant HFC-
134a (R-134a) and specified lubricants.

RHA272D

SERVICE HOSES

Be certain that the service hoses display the markings described
(colored hose with black stripe). All hoses must include positive
shut off devices (either manual or automatic) near the end of the
hoses opposite the manifold gauge.

PRECAUTIONS AND PREPARATION

HA-14

RHA273D

SERVICE COUPLERS

Never attempt to connect HFC-134a (R-134a) service couplers to
an CFC-12 (R-12) A/C system. The HFC-134a (R-134a) couplers
will not properly connect to the CFC-12 (R-12) system. However, if
an improper connection is attempted, discharging and contamina-
tion may occur.

Shut-off valve rotation

A/C service valve

Clockwise

Open

Counterclockwise

RHA274D

REFRIGERANT WEIGHT SCALE

Verify that no refrigerant other than HFC-134a (R-134a) and speci-
fied lubricants have been used with the scale. If the scale controls
refrigerant flow electronically, the hose fitting must be 1/2

″

-16

ACME.

CALIBRATING ACR4 WEIGHT SCALE

Calibrate the scale every 3 months.
To calibrate the weight scale on the ACR4 (J-39500-INF):
1.

Press Shift/Reset and Enter at the same time.

Press 8787. “A1” will be displayed.

Remove all weight from the scale.

Press 0, then press Enter, “0.00” will be displayed and change
to “A2”.

Place a known weight (dumbbell of similar weight), between 10
and 19 lbs., on the center of the weight scale.

Enter the known weight using 4 digits. (Example 10 lb = 10.00,
10.5 lb = 10.50)

Press Enter — the display returns to the vacuum mode.

Press Shift/Reset and Enter at the same time.

Press 6 — the known weight on the scale is displayed.

10. Remove the known weight from the scale. “0.00” will be dis-

played.

11. Press Shift/Reset to return the ACR4 to the program mode.

CHARGING CYLINDER

Using a charging cylinder is not recommended. Refrigerant may be
vented into air from cylinder’s top valve when filling the cylinder
with refrigerant. Also, the accuracy of the cylinder is generally less
than that of an electronic scale or of quality recycle/recharge equip-
ment.

IDX

PRECAUTIONS AND PREPARATION

Precautions for Service Equipment (Cont’d)

HA-15

Refrigeration Cycle

REFRIGERANT FLOW

The refrigerant flow is in the standard pattern. Refrigerant flows through the compressor, condenser, liquid
tank, evaporator, and back to the compressor.
The refrigerant evaporation through the evaporator coil is controlled by an externally pressure equalized
expansion valve, located inside the evaporator case.

FREEZE PROTECTION

Under normal operating conditions, when the AUTO is switched ON, the compressor runs continuously, and
the evaporator pressure, and therefore temperature, is controlled by the V-6 variable displacement compres-
sor to prevent freeze up.

REFRIGERANT SYSTEM PROTECTION

Triple-pressure switch

The triple-pressure switch is located on the liquid tank. If the system pressure rises or falls out of specifications,
the switch opens to interrupt compressor clutch operation. Triple-pressure switch closes to turn on the cool-
ing fan to reduce system pressure.

Fusible plug

Opens at temperatures above 105°C (221°F), thereby discharging refrigerant to the atmosphere. If this plug
is melted, check the refrigerant line and replace liquid tank.

RHA896F

DESCRIPTION

HA-16

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