Mazda TC070-15-01H, Руководство для студентов

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AIR CONDITIONING
SG02 - Control System [Manual Air Conditioning]
SG02-11
TC070-15-01H
Refrigerant pressure switch
The figure below shows a triple pressure type refrigerant pressure switch that
consists of the low/high-pressure switch and the medium-pressure switch. The
low/high-pressure switch protects the refrigerant cycle by cutting the A/C signal when
pressure in the refrigerant cycle is either abnormally high or low. The medium-
pressure switch outputs an idling increase signal according to the A/C compressor
operation load.
Why do you think the system needs to cut the A/C signal when pressure in the
refrigerant cycle is abnormally low? How does it affect the system?
Medium-pressure switch operates when the refrigerant pressure is approx. 1.52 kPa
{14.2 kgf·cm2, 202 psi} or more. When it operates, the contact is closed to send an
“Idling increase signal” to the PCM. When the A/C is on and an Idling increase signal
is input to the PCM, it sends an operation signal to the IAC solenoid valve.