Atlas Copco CD 480

Instruction Book
9829 2115 69 20
drying tower. When the PDP temperature is below the set point then the drying tower will keep
on drying until the PDP temperature exceeds the set point. Then the regenerated tower will
start drying the compressed air and the other tower will be regenerated.
PDP controls are optional on CD dryers, standard on CD+ dryers. This option can be added
at any time. Consult section 8.1 for instructions.
2.5 Operating cycles
Description
The CD dryer is controlled by a Elektronikon or Timer card regulator. The main cycle steps
are as follows:
Step Function of tower A Function of tower B Time
0
Adsorbing Blow-off and regenerating 195 s
1
Adsorbing Pressurizing 55 s
2
Blow-off and regenerating Adsorbing 195 s
3
Pressurizing Adsorbing 55 s
The regulator will display a warning if the operating pressure drops below the minimum
setting of 65.3 psig (4.5 bar(e)). (Elektronikon only)
When the dryer is restarted (e.g. after a power failure or a shut-down) from a step in
which one of the vessels was depressurized, the blow-off valve will open for some time
to make sure that the pressure is released. The dryer will continue the cycle, starting
from the cycle step where it was stopped or where the power failure or shut-down
occurred.
For working applications below 65.3 psig (4.5 bar(e)) special provisions are to
be taken on the dryer selection (Consult Atlas Copco).
For working applications below 65.3 psig (4.5 bar(e)) special provisions are to be taken on the dryer
selection (Consult Atlas Copco).
The display shows which cycle steps the towers are working in, making it easy to follow
the operation. The display can also indicate inlet temperature, pressure and time
settings, as well as the pressure dewpoint, etc.