Cincinnati Sub-Zero ZP Series - Page 84

MAINTENANCE WITH Q & A
72
DRY AIR PURGE TROUBLESHOOTING PROCEDURES (OPTIONAL EQUIPMENT)
PROBLEM
PROBABLE CAUSE
CORRECTIVE ACTION
Excessive drop
in outlet
pressure
Improper operating conditions
Correct operating conditions
Solenoid coil burned out
Remove cover, place iron or steel material (screwdriver or
nail) on exposed end of solenoid base to
feel the magnetic
effect indicating proper operation. Each coil should be
energized for 30 seconds. Depress switch
lever by hand and
listen for clicking contact. Switch should click when
depressed and when released. Replace if necessary.
Improper cycle timer operation
Check the power supply. If the correct voltage is not present
between L1 and both of the L2 term
inals, check the wiring
and protective device supplying power to the dryer.
Dryers with DC solenoid valves should alternately have DC
voltage between L2 and DC1 and between L2 and DC2.
Replace the timer if voltage is present at either DC terminal
conti
nuously or not at all.
Timer Input 120VAC/Timer Output 53 VDC
Timer Input 240 VAC/Timer Output 106 VDC
Timers P-06521-F1 and F2 are the standard timers used on
the HF200, HF300A and HF300B air driers. The timers permit
simultaneous switching of t
he solenoid valves every 30
seconds.
Check valve balls for proper
seating
Remove check balls and springs and inspect for excessive
wear or damage. Replace if necessary
Plugged air passages
Check inlet and outlet air passages and piping for blockage.
Correct if necessary.
Desiccant attrition or
contamination
Inspect outlet air line for indication of excessive oil.
Check operation of dropout filter.
Remove chamber from manifold and depress perforated disc
at open end of chamber. If it can be de
pressed more than
1/4" from the retaining ring, replace chamber.
Solenoid valve
chatter
Solenoid valve defective
Replace solenoid valve core assembly and solenoid base.
Table 5-6: Dry Air Purge Troubleshooting Procedures (Continued)