warning NISSAN 300ZX 1984 Z31 Heather And Air Conditioner Workshop Manual

DESCRIPTION-Air Conditioner (Manual)
Refrigerant Leak Warning System
The refrigerant leak warning system, used in con-
junction with the low-pressure switch, protects the
cooler cycle from damage due to continued opera-
tion of the
air conditioning system when there is a
shortage of refrigerant
It also indicates when to re-
plenish the refrigerant
Refrigerant leak
warnmg lamp Recirculation switch
Air conditioner switch
control lever
SHA227B
I ll I
SHA2286
When the refrigerant in the cooler cycle is insuffi-
cient,
it vaporizes quickly inside the evaporator As
a result, the "super heat" of the refrigerant at the
outlet of the evaporator increases
If it exceeds the
specified level [Approximately 45°C
(8l0F)1, the
super heat switch turns on, allowing the current to
flow through the timer If current continues to
flow through the timer for the specified length of
time, the timer activates to close the contacts
which turn on the warning lamp
Leak warning lamp check
Conduct a continuity test in the leak warning lamp
circuit.
1) Turn ignition switch "ON" (with engine off) to
make sure warning lamp illuminates.
2) Start engine. Warning lamp should go out if the
amount of refrigerant
is sufficient.
EXPLANATION OF SUPER HEAT
When a liquid under constant pressure inside a
cylinder is heated, it apparently changes in three
different
states The relationship between the tem-
perature of the liquid (refrigerant) and
its volume,
which
uses the pressure as a parameter, is shown in
the graph below.
1) The temperature of the liquid rises along the
saturated liquid line (a -+ b or a + b')
2) When the temperature of the liquid reaches a
certain level, evaporating bubbles quickly ap-
pear This mixture of liquid and vapor contin-
ues to take place, during which the tempera-
ture remains constant until the
last droplet of
liquid vaporizes. Points c and c' where the
entire liquid vaporizes, are located on the
saturated vapor line (b
+ c or b -+ c').
3) When the liquid is further heated, the tempera-
ture of the vapor
rises again and its volume also
increases.
The volume will continue to increase
as the temperature is increased
We call this vapor "super heated vapor" (c + d
or c'
+ d')
The line between points c and c'
is called the
"saturated vapor line."
HA-I 0

DISCHARGING, EVACUATING, CHARGING AND CHECKING
Precautions
WARNING:
Always be careful that refrigerant does not
come in contact with your skin.
Always wear
eye protection when working
around the
system
Keep refrigerant containers stored below 50°C
(122" F) and never drop it from a high place
Work
in well-ventilated area because refrigerant
gas evaporates quickly and breathing may be-
come difficult due to the lack of oxygen
Keep refrigerant away from open flames
be-
cause poisonous gas will be produced if it is
burns.
Do not use steam to clean surface of condenser
or evaporator
Be sure to use cold water or
compressed air.
Compressed
air must never be used to clean a
dirty line Clean with refrigerant gas
Do not use manifold gauge whose press point
shape
is different Otherwise, insufficient
evacuating may occur
fJalve press point
NG SHA919A
Do not over-tighten service valve cap.
Do not allow refrigerant to rush out. Other-
wise, compressor oil will
be discharged along
with refrigerant
Discharging
Slowly open the valves to discharge only refriger-
ant If they
are opened quickly, compressor oil will
also be discharged
To low-pressure IerYlCe valve
To high-pressure service valve
*
SHA240B
4c==--J
HA-I 2

DISCHARGING, EVACUATING, CHARGING AND CHECKING
0 (0)
300 /1,000)
Evacuating The System
1. Start pump, then open both valves and run
pump for about 20 minutes
-. -
101 3 (760.29 92)
98
0 (735.28 94)
To high-pressure serwce valve To low-pressure
600 (2,000)
Vacuum pump
94 6 (710.27 95)
SHA241 B
900 (3.000)
2. When low gauge has reached approx 101 3 kPa
(760 mmHg, 2992 inHg), completely close
both valves of gauge and stop vacuum pump
Let
it stand for 5 to 10 minutes in this state
and confirm that the reading does not rise.
a. The low-pressure gauge reads lower by 3.3 kPa
(25 mrnHg, 0.98 inHg) per 300 rn (1.000 ft)
elevation Perform evacuation according to the
following table.
91 3 (685.26 97)
I
Vacuum of system*
kPa
(mmHs. inHal
Elevation
m (ftl
* Values show reading of the low-pressure gauge
b. The rate of ascension of the low-pressure gauge
should be less than
3.3 kPa (25 mmHg, 0.98
inHg) in five minutes.
- Charging
1 Evacuate refrigerant system
2
Close manifold gauge valves securely and dis-
connect charging hose from vacuum pump
3 Purge air from center charging hose
1) Connect center charging hose to refrigerant can
through can top
2) Break
seal of refrigerant can and purge air
SHA2428
4 Charge refrigerant into system
WARNING:
Ensure that engine is off.
1) Open high- and low-pressure valves of manifold
gauge and charge refrigerant into system
SHA243B
HA-I 3

DISCHARGING, EVACUATING, CHARGING AND CHECKING
Chargin!
2) Quick charging
Immerse in water heated to about40*C 11W0FI for a Short time
AC184A
CAUTION.
If charging liquefied refrigerant into the system
with the can turned upside down to reduce charg-
ing time, charge it only through high pressure (dis-
charge) service valve. After charging, the compres-
sor should always be turned several times manual-
ly.
To high-pressure sermce valve To low-pressure
SHA244B
5. When refrigerant charging speed slows down,
charge
it while running the compressor for ease
of charging
WARNING:
Never charge refrigerant through high pressure side
(discharge
side) of system since this w~ll force re-
frigerant back into refrigerant can and can may
ex-
plode.
Cont'd)
Run at Idling (Below 1.500 rpml
To high-pressure servlce valve
II
To low-pressure IerUlCe valve
@g Fan lever, made and temperature dial Maximum cool and speed
I? SHAZ~SB
Charge refrigerant while controlling low-pres
sure gauge reading
at 275 kPa (2 8 kg/cm2, 40
psi) or less by turning in or out low-pressure
valve of manifold gauge.
Be sure to purge air from charging hose when
replacing can with a new one.
Charge the specified amount of refrigerant into
system by weighing charged refrigerant with
scale Overcharging will cause discharge pres-
sure
to rise.
Refrigerant amount:
MJS170
0.9 - 1.1 kg (2.0 - 2.4 Ib)
SHA9OOA
HA-I 4

PRECAUTIONS FOR REFRIGERANT CONNECTION
WARNING.
Gradually loosen discharge side hose fitting, and re-
move
it after remaining pressure has been released
When replacing or cleaning refrigerant cycle com-
ponents, observe the following
Do not leave compressor on its side or upside
down for more than 10 minutes, as compressor
oil will enter low pressure chamber
When connecting tubes, be sure to
use a torque
wrench
torque wrench
SHA896A
After disconnecting tubes, plug all openings im-
mediately to prevent entrance of dirt and mois-
tu
re
Plug
SHA058
Do not reuse used O-ring
When connecting tube, apply compressor oil to
portions shown in illustration
Be careful not
to apply oil to threaded portion
O-ring must be closely attached to inflated por-
tion of tube
NG
lnflaied pomon
OK - SHA897A
After inserting tube into union until O-ring is
no more visible, tighten nut to specified tor-
que
u"'06a e GO K GN G 7
b
SHA898A
After connecting line, conduct leak test and
make sure that there
IS no leak from connec-
tions When the
gas leaking point IS found, dis-
connect that line and replace the O-ring Check
fit for further use and then tighten connections
to seal seat for the specified torque
HA-20