Compressor - Fiat Punto 2004 Training Manual

AIR CONDITIONER
MAX DEF function actuator;
rear heated window actuator.
D) connecting lines with:
Body Computer CAN network.
Nuova Punto is equipped with the variable-displacement, magnetic clutch-free Denso 5SL12
compressor. It makes it possible to gradually vary the flow rate of the cooling fluid reaching the
evaporator; as a result, the anti-frost sensor would be redundant and has therefore not been
fitted to the system.
Control is based on the intake pressure value, according to the following logic:
low pressure: the compressor displacement tends to the minimum value;
high pressure: the displacement is increased.
This operating logic refers to the following actual conditions:
"low pressure" means that the load imposed to the air conditioner is such that it does not
require very high fluid flow rate;
"high pressure" means that a very high load is imposed to the air conditioner, and the required
amount of cooling fluid is great.
Operation
The pulley motion is transmitted continuously to the compressor shaft by means of jumpers,
referred to as "limiters" (3), which are interrupted in case of seizure due to a compressor fault,
thus preventing the pulley from getting stuck and, therefore, the auxiliary member belt from
being broken.
In order to reduce the torque fluctuations that generate noise, special dampers referred to as
"dumpers" (4) and an inertia ground (5) directly secured to the shaft are also used.
Since the motion is always transmitted to the compressor shaft, the compressor switch-on/off
function is entrusted to the "ON/OFF" valve (6).
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