Atlas Copco GA 11 VSD MED, Instruction Book

Page: 16 / 104

2.5 Condensate system
Condensate drains
Condensate drain connections
The compressors have a condensate trap (MT) downstream the air cooler. The condensate trap is provided
with a manual drain outlet (Dm) and an automatic drain outlet (Da).
2.6 Regulating system
Unloading valve assembly (loaded condition)
Description
If the consumption is less than the air output of the compressor, the net pressure increases. When the net
pressure is higher than the set-point (desired net pressure), the regulator will decrease the motor speed. If the
net pressure keeps on rising when the motor runs at minimum speed, the regulator stops the motor. If the
motor is stopped automatically and the net pressure approaches the set-point, the regulator will restart the
motor.
Unloaded operation
If the air consumption is less than the air output of the compressor, the net pressure increases. When the net
pressure reaches the unloading pressure, solenoid valve (Y1) is de-energised.
• The pressure above loading plunger (LP) and unloading valve (UV) is vented to atmosphere via solenoid
valve (Y1).
• Loading plunger (LP) moves upwards by spring force and causes inlet valve (IV) to close the air inlet.
Instruction book
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