Performance Test - Mazda MX-5 1990 Workshop Manual

u
U-30
HOW TO READ THE GRAPH:
AIR CONDITIONER
05UOUX-048
05UOUX-050
4. Charge the system with the specified amount of refrigerant.
Specified amount: 800 g (28.24 oz)
5. Close the low-pressure manual valve and the service valve
of the refrigerant container.
6. Carry out a performance test (Refer to below.).
7. Stop the air conditioner and the engine.
8. Quickly disconnect both hoses from the gauge fittings.
9. Put the cap nuts on the gauge fittings.
Performance test
After finishing repairs, conduct a performance test of the air
conditioning system as follows.
1. Connect the manifold gauge set. (Refer to page U-28.)
2. Start the engine and keep the engine speed at 1,500 rpm.
3. Operate the air conditioner at maximum cooling.
4. Open all windows and doors.
5. Place a dry-bulb thermometer in the center ventilator outlet.
6. Place a dry and wet thermometer close to the blower inlet.
7. Wait until the air conditioner outlet temperature stabilizes.
Stabilized condition
Blower inlet temperature: 25-35°C (77-95°F)
High-pressure side:
1,177-1,619 kPa (12.0-16.5 kg/cm2, 171-235 psi)
Note
• If the high-pressure side becomes too high, pour
cool water on the condenser. If it is too low, cover
the front of the condenser.
8. After the air conditioner stabilizes, read the dry and wet ther-
mometer at the air inlet.
9. Calculate the relative humidity from the chart below by com·
paring the wet- and dry-bulb readings.
05UOUX-051
AFTER MEASURING THE TEMPERATURES OF WET- AND
DRY-8UL8 THERMOMETERS AT THE EVAPORATOR AIR
INLET, RELATIVE HUMIDITY (%) CAN BE OBTAINED.
EXAMPLE: SUPPOSING DRY- AND WET-BULB TEMPERA-
TURES AT EVAPORATOR AIR INLET ARE
25°C
AND
19.5°C
RESPECTIVELY THE POINT OF INTERSECTION OF THE
DOTTED LINES IN THE GRAPH, AND IS 60%.
~43710
-~ ~--~-.--
.--
- - - - - - - - - - - , - - - - - - - - - - - - - - - - - - - - - - - - - -