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Chery S11 / Chery QQ. Manual - part 73

Chery QQ Service Manual

The ECU makes the low speed relay operating after receiving the A/C switch closed

signal, then the fan begins to work. When the water temperature is higher than certain

degree, ECU will make the fan‘s high speed relay operating automatically, then the

high speed fan works.

The pressure switch in this circuit is fitted on the side of the high pressure loop (i.e.

drying bottle mouth) of the air conditioning cooling midum loop, its function is to

protect refrigeration loop when abnormal pressures occurs due to over-charged

refrigerant or gas leakage. Pressure switch signals are sent to the ECU that will stop

the compressor by disconnecting the air conditioner relay when the pressure switch

disconnects for some reasons.

The temperature sensor in this circuit is an electric one (thermistor), the resistance

value of which changes as temperature changes. So the thermistor connects or

disconnects the electric magnetic clutch, drive or stop the compressor by sensing air

temperature blew by air conditioner. Therefore it can control the interior temperature

and avoid frosting to make a constant temperature.

The ECU controls the compressor’s electric magnetic clutch and condensator fan

motor on basis of detecting the running condition for engine and signals from sensors.

ECU will connect air conditioner and condensator fan only when the following

conditions are met:

Engine rotate speed: 600-6000r/min

Engine cooling temperature:below 110℃

Evaporator temperature:over 4℃

Refrigerant pressure switch:on

AC switch and the air blower switch:on

Section 2 Safety Cautions for Air conditioning System

1. Do not deal with the refrigerant in closed place or colse to fire.

2. Be sure to take safety goggles.

3. Take good care of the refrigerant. Avoid the liquid refrigerant to splash into your

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eyes and skin. If it occurs, wash with cooled water.

Warning: (a) Do not wipe your eyes or skin.

(b) Clean the oil on your skin properly

4. Do not heat container or put it close to fire.

5. Put the reservoir carefully and avoid it to be impacted with sharp object.

6. Refrigerating system used outdoor must have enough refrigerant, otherwise the

compressor will burn due to thus insufficient lubricant oil. So you should take care of

such case.
7. Do not turn on the pressure combined vaccum valve when compressor is running.
  If the high-pressure valve is turned on the refrigerant will flow at inverse direction
and result in breakdown of the chargeing cyliner body, therefore only the low pressure
valve can be switched.

8.  Do not make system with refrigerant overloaded.
  If the refrigerating unit is overloaded, then a series of problems will take place.
For example, insufficient refrigeration, reduction of fuel effitioncy, overheating of
engine and etc.

9. Spare control system
This model of car is equiped with spare control system, such as air bag in drive cab
and fore carriage.

In maintenance, in case of operatation not in order, the spare system will unfold, thus
resulting in series of accidents. So maintenance workers should read carefully
precautions of the air bag before operating (including movement, installation, check
and removal for air bag).

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Chery QQ Service Manual

Section 3 Items of Tools and Devices

Disassembly tool for magnetic clutch

Retainer for magnetic clutch

Spring clasp clamp

Lip sealing protection

Maintenance kit for air conditioner

Spare valve for discharging refrigerant

Refrigerant charge meter

Refrigerant charge hose

green

Refrigerant charge hose

blue

Refrigerant charge hose

orange

Disconnecting valve

Set of charge hoses with diconnecting

valve

if diconnecting valves are

needed, please order (in set)

Section 4 Operating Method for the Manifold Pressure Meter

As shown in the fingure, the manifold pressure meter is the most common meter used
for air conditioning unit maintenance. The low-pressure meter can show both pressure

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Chery QQ Service Manual

and vacuum. The vacuum range is 0-5X10

pa(0-760mmHg), the pressure scale starts

from 0 and range is over 4.2X10

pa(approximate 4.2kgf/cm

). The high-pressure

meter scale starts from 0 and range is over 21.1X10

pa(approximate 21.1kgf/cm

These two meters are fitted on the same seat, each end of which has a manual valve
and under which there are three path joint.
Joint of low-pressure meter, that connnects to low pressure pipe connector through a
hose.

70141

Manifold pressure meter

1- Lowe-pressure meter(blue) 2-high-pressure meter(red) 3- hose at high pressure
side (red) 4- hose for maintainance (yellow) 5- hose at low pressure side (blue)

Joint for high-pressure meter connects to the high pressure pipe with a hose. The
middle joint connects to the vaccum pump or refrigerant tank with a hose. Two
manual valves combined with three hoses make the manifold pressure meter have four
functions(as shown in below diagram)

Functions of the manifold pressure meter

positions of the high and low pressure valves

functions

high and low pressure valves off

Fault diagonosis for the refrigeration system

Low pressure valve on, high pressure valve off

Filling refrigerant or refrigerant oil

in refrigeration system

Low pressure valve off, high pressure valve on

Check leakage of the refrigeration system and

charge liquid quickly

high and low pressure valves on

Evacuate the refrigeration system

Note:

high and low pressure valves are on, which means that the two meters are connect ed to

refrigeration system and middle pipe respecdtively; high and low pressure valves are off, which

means that the two meters are disconnected to the middle pipe but connected to refrigeration

system.

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