AEC AP Series Large Dehumidifying Dryer - Manual (Page 66)

Large Dehumidifying Dryers Controls 65
A security tier is activated by entry of the proper password. Once activated, that tier will
remain active until:
• The customer manually logs off.
• The tiers active duration time expires.
• Power is cycled.
• The tiers password is changed to 0000.
4-9 Dryer & Drying Hopper Faults
AP1+ faults fall into two broad categories.
• Critical Faults – Shuts down equipment.
• Non-Critical Faults – Does not shut down equipment.
Critical faults are assigned to conditions that could cause damage to either the dryer
components or the material in the drying hopper while non-critical faults are assigned to
conditions that would allow an undesirable or inefficient Process condition to exist.
Because the Process and regeneration systems of the AP1+ dryer operate independently, is
possible that a condition exists in the regeneration system that prevents it from operating
while the Process system continues to operate without error.
When a fault condition occurs, the AP1+ displays an “Alarm Banner” showing the time, date
and a brief description of the alarm. Optionally, the AP1+ will sound a klaxon and turn on an
alarm lamp. The alarm banner, klaxon and lamp do not distinguish between critical and non-
critical alarms. The klaxon can be silenced and the alarm lamp turned off by pressing the
“Push to Silence” button on either the alarm banner or alarm history display. However,
depending on the customer’s setup, the klaxon and lamp may repeat after a pre-set time if the
alarm condition still exists.
If a dryer critical fault occurs then either a “Process Fault Push to Reset” or a “Regen Fault
Push to Reset” button appears on the overview displays. Press the button to restart the failed
system once the nature of the alarm is understood and corrected.
If a drying hopper critical fault occurs then disable and re-enable the drying hopper once the
fault has been corrected.
Section [X] contains a list of all the alarms the AP1+ is capable of detecting and their effect
on their associated system however some generalizations can be made.
• If something should be “ON” and it’s “OFF” or vice versa.
o Blower Motor Overloads should always be “ON”.
o Heater isolation contactors should be “ON” when the heaters are in use and OFF
otherwise.
• If a value is less than a pre-set limit.
o Process supply air temperature low deviation alarm.
• If a value is greater than a pre-set limit.
o Dryer high dew point alarm.