Nissan Primera P11. Instruction — part 465
RHA896FA
Pressure relief valve (CSV613 only)
Outside air
Compressor
Condenser
Liquid tank
Dual-pressure switch/ pressure sensor
Expansion valve
Blower motor
Evaporator
High-pressure
gas
High-pressure
liquid
Low-pressure
liquid
Low-pressure
gas
DESCRIPTION
Refrigeration Cycle (Cont’d)
HA-13
CSV613 Variable Displacement Compressor
GENERAL INFORMATION
1. The CSV613 compressor differs from previous units. The vent temperatures of the CSV613 compress
or do not drop too far below 5°C (41°F) when:
●
evaporator intake air temperature is less than 20°C (68°F)
●
engine is running at speeds less than 1,500 rpm.
This is because the CSV613 compressor provides a means of “capacity” control.
2. The CSV613 compressor provides refrigerant control under varying conditions. During cold winters, it
may not produce high refrigerant pressure discharge (compared to previous units) when used with air
conditioning systems.
3. A “clanking” sound may occasionally be heard during refrigerant charge. The sound indicates that the
tilt angle of the swash plate has changed and is not a problem.
4. For air conditioning systems with the CSV613 compressor, the clutch remains engaged unless: the sys-
tem main switch, fan switch or ignition switch is turned OFF. When ambient (outside) temperatures are
low or when the amount of refrigerant is insufficient, the clutch is disengaged to protect the compressor.
5. A constant range of suction pressure is maintained when engine speed is greater than a certain value.
It normally ranges from 147 to 177 kPa (1.47 to 1.77 bar, 1.5 to 1.8 kg/cm
2
, 21 to 26 psi) under vary-
ing conditions.
In previous compressors, however, suction pressure was reduced with increases in engine speed.
DESCRIPTION
HA-14
DESCRIPTION
General
The variable compressor is basically a swash plate type that changes piston stroke in response to the
required cooling capacity.
The tilt of the swash plate allows the piston’s stroke to change so that refrigerant discharge can be continu-
ously changed from 6 to 125 cm
3
(0.366 to 7.63 cu in).
KHA103
Shaft
Seal
Journal pin
Swash plate
Rear Head
Discharge
valve plate
Control valve
Cylinder
Piston
Oil drain bolt
Swash plate
tilting angle
changes
Long stroke
(Large amount of refrigerant discharge)
Short stroke
(Small amount of refrigerant
discharge)
Drive lug
Journal pin
Discharge
control
Discharge
capacity
cm
3
(cu in)/rev.
Pistonstroke
length
mm (in)
Minimum
6 (0.366)
1.2(0.039)
Maximum
125 (7.63)
25.9 (1.02)
DESCRIPTION
CSV613 Variable Displacement Compressor
(Cont’d)
HA-15
Operation
1. Operation control valve
Operation control valve is located in the suction port (low-pressure) side, and opens or closes in response
to changes in refrigerant suction pressure.
Operation of the valve controls the internal pressure of the crankcase.
The angle of the swash plate is controlled between the crankcase’s internal pressure and the piston cyl-
inder pressure.
2. Maximum cooling
Refrigerant pressure on the low-pressure side increases with an increase in heat loads.
When this occurs, the control valve’s bellows compress to open the low-pressure side valve and close
the high-pressure side valve.
This causes the following pressure changes:
●
the crankcase’s internal pressure to equal the pressure on the low-pressure side;
●
the cylinder’s internal pressure to be greater than the crankcase’s internal pressure.
Under this condition, the swash plate is set to the maximum stroke position.
RHA473C
Discharge port
Suction port
Crankcase
Low-pressure valve: Open
Bellows
Valve position for lowering
crankcase pressure
Spring pressure
Cylinder pres-
sure
Crankcase pres-
sure
Forces needed to increase stroke
DESCRIPTION
CSV613 Variable Displacement Compressor
(Cont’d)
HA-16
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