AC compressor regulating valve -N280
A and B - Connector
of AC compressor regulating valve -N280 -N280
The electric AC
compressor regulating valve -N280 is pushed into the compressor and is secured
by a spring ring.
It forms the interface
between the low, high and crankcase pressure in the compressor and is the
precondition for clutchless operation.
The adjustment of the
swash plate is effected by these different pressures.
That means, if a higher
cooling power is required, for example, the regulating valve is activated by
the Climatronic control unit -J255.
A pulse width modulated
voltage signal moves the plunger in the regulating valve. The duration
of the applied voltage determines the adjustment travel.
The adjustment alters
the opening cross-section between the high pressure and the pressure in the
crankcase of the compressor. The crankcase pressure increases and, by way of
the piston stroke, effects a greater skew of the swash plate.
J If an
inadequate vehicle voltage is applied, faults may occur in the air conditioning
system, or it may fail altogether.
J If the
regulating valve fails, the wash plate positions itself perpendicular to the
longitudinal axis of the compressor such that the cooling function is disabled.
conditioner; Rep.Gr. 87; Checking switch-on signal for AC compressor regulating
A Current flow