Sullair SD Series - Dryer Failure to Switch Over Troubleshooting

INSTALLATION, START-UP & MAINTENANCE MANUAL
MODEL NO.: SD-820 / SD-1710
REV 1 – AUGUST 03,.2001
Page 48
SECTION 7
7.2 THE ADSORPTION DRYER DOES NOT SWITCH OVER
Possible cause Solution
•
Chamber pressure switch contact is
defective (
1
)
⇒
Verify switch contact and replace if
necessary
•
Chamber pressure below pressure
switch settings (
1
)
•
Exhaust valve not fully closed
•
Solenoid valve leaks
•
Purge isolation valves partially open
or closed
⇒
Set switch 30 PSIG below normal operating
pressure
⇒
Verify valve for obstruction. Verify pilot air to
exhaust valve is removed during the repress
stage
⇒
Verify for air leakage on non-activated
solenoid
⇒
Purge isolation valves (2) are to be fully
open at all times
•
Inlet valve failed to operate position
⇒
Verify pilot air to inlet valve actuator.
⇒
Verify solenoid valve.
•
Inlet/exhaust valve failed to activate
⇒
Verify wiring to terminal strip
⇒
Verify wiring connector on the solenoid valve
assembly
⇒
Verify pilot air service valve is open
⇒
Verify pilot air filter element is not soiled
•
Outlet check valve failed to close
⇒
Verify bushings on check valve are worn
⇒
Verify spring on check valve
⇒
Verify check valve seat o’ring
(1) Dryers with DDS option.