стр.7 PWM (PULSE WIDTH MODULATION) ELECTRIC FAN OPERATION 1) Function

PWM (PULSE WIDTH MODULATION) ELECTRIC FAN OPERATION 1) Function

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3. PWM (PULSE WIDTH MODULATION) ELECTRIC FAN
OPERATION
1) Function
The PWM (Pulse Width Modulation) high capacity electric fan is installed instead of electric
condenser fan to enhance the durability and controllability and reduce noise.
2) Mounting Location
Fan shroud
PWM unit Electric fan
ENGINE COOLING SYSTEM
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3) PWM Electric Fan
(1) Advantages and Disadvantages of the PWM Electric Fan
Advantages
- Enhanced A/C performance: at low
speed, at idling, driving in city
- Reduction of vibration/noise: fan
activated by PWM only when necessary
- Reduction of engine consuming power
(V/Fan driving force) by Hp - Cost
saving
Disadvantage
- Poor engine cooling perfomance at low
and high rpm
4) PWM (Pulse Width Modulation) Unit
It controls the time of the output voltage to
control the fan motor speed independently.
Internal functions
- Motor power shutting-off function when
overcurrent is applied
- Adverse voltage prevention function
- Detection function for the motor lock
- Temperature detecting function: The
electric fan operates at FULL speed to
cool down the PWM unit when the
interior
temperature of PWM unit is over
~ °C.
- Communication function when failing:
The fail signal is transmitted to the ECU
when the PWM unit is malfunctioning.
- Soft start function: The motor speed is
gradually increased when the motor is
initially operated.
ENGINE COOLING SYSTEM
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5) Shutting-off Condition of the A/C Compressor
Coolant temperature
- When coolant temperature is below °C or over °C, engine speed is below
rpm or over rpm for seconds after engine starting, abrupt acceleration and A/C
refrigerant pressure sensor detecting the followings
- A/C compressor is turned off when the refrigerant pressure is below 2.0 kg/cm2 and then
is turned on when the refrigerant pressure is over 2.4 kg/cm2.
- A/C compressor is turned off when the refrigerant pressure is over kg/cm2 and then
is turned on when the refrigerant pressure is below.4 kg/cm2.
ENGINE COOLING SYSTEM
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