MANUAL CONTROL HVAC SYSTEM 7C-3
SSANGYONG Y200
Receiver-Drier
The sealed receiver-drier assembly is connected
between the condenser and evaporator. It acts as a
refrigerant storing container, receiving liquid and some
vapor and refrigerant oil from the condenser.
At the bottom of the receiver-drier is the desiccant,
which acts as drying agent for the moisture that may
have entered the system. An oil bleed hole is located
near the bottom of the receiver-drier outlet pipe to
provide an oil return path to the compressor. The
receiver drier is serviceable as an assembly.
Expansion Valve
The expansion valve can fall in three different positions:
open, closed or restricted.
An expansion valve that fails in open position will result
in a noisy A/C compressor or no cooling. The cause
can be a broken spring, a broken ball or excessive
moisture in the A/C system. If the spring or the ball
are found to be defective, replace the expansion valve.
If excessive moisture is found in the A/C system
recycle the refrigerant.
A restricted expansion valve will result in low suction
pressure and no cooling. This may be caused by debris
in the refrigerant system. If debris is believed to be
the cause, recycle the refrigerant, replace the
expansion valve and replace the receiver-drier.
Evaporator
T h e e v a p o r a t o r i s a d e v i c e w h i c h c o o l s a n d
dehumidifies the air before it enters the vehicle. High
pressure liquid refrigerant flows through the expansion
tube (orifice) and becomes a low pressure gas in the
evaporator. The heat in the air passing through the
evaporator core is transferred to the cooler surface or
the core, which cools the air.
As the process of heat transfer from the air the
evaporator core surface is taking place, any moisture
(humidity) in the air condenses on the outside surface
of the evaporator core and is drained off as water.
Pressure Relief Valve
The compressor is equipped with a pressure relies
valve which is placed in the system as a safety factor.
Under certain conditions, the refrigerant on the
discharge side may exceed the designed operating
pressure at approximately at 3,171 to 4,137 kPa
(460 to 600 psi) in an R-134a system. Conditions that
might cause this valve to open, such as a defective
pressure transducer, an inoperative cooling fan, etc.,
should be corrected. The refrigerant oil and the
refrigerant should be replaced as necessary.
Controller
The operation of the A/C system is controlled by the
switches and knob on the control head. This console-
mounted controller contains following control knobs.
Rotary Temperature Control Knob
•
Actuates by cable.
•
Raise the temperature of the air entering the vehicle
by sliding to the right or the red portion of the knob.
•
Varies the mix of the fresh air from outside the
vehicle with the heated air from inside the vehicle
to suit individual performance.
Rotary Mode Control Knob
•
Actuates by cable.
•
Re g ulat e s t he a ir dis t rib ut ion b e t we en t he
windshield, the instrument panel and the floor vents.
Rotary Blower Control Knob
•
Turn on to operate the blower motor at four speeds.
•
Turn OFF to stop the blower.
•
Operates completely independently from both the
mode control knob and temperature control knob.
•
Changes the fan speed in any mode and at any
speed.