Pub. No. OM-A-10E — April 2004
21
OPTIONS LISTING WITH EXPLANATION
AUDIBLE ALARM
The Audible Alarm consists of a buzzer with reset push
button and ON/OFF selector switch.
The audible alarm provides an audible warning to alert
an operator that the dryer is not functioning properly. This
option is used with options such as “Failure to Shift Alarm”
or “High Humidity Alarm.”
FAILURE TO SHIFT ALARM
The Failure to Shift Alarm consists of an alarm light that
illuminates if the desiccant towers fail to shift at a
prescribed time. Dry contacts are provided for remote
annunciation.
HEATER FAILURE ALARM
The Heater Failure Alarm consists of an alarm light that
illuminates if the heater fails to reach design temperature
during regeneration. The time delay relay shall be set at
3 hrs. and the thermostat set at 200°F. Dry contacts are
provided for remote annunciation.
HIGH HUMIDITY ALARM
The High Humidity Alarm consists of an alarm light
controlled by a hygrometer that senses the dewpoint at the
outlet of the air dryer. This alarm illuminates when the
dewpoint reaches -20°F and above. A small amount of
sample air is required for operation. Dry contacts are
provided for remote annunciation.
Calibration:
To maintain accuracy, replace the probe
every two years.
Probe Replacement:
Turn the normal/demand selector
switch to the normal position. This will disable the contacts
for Dewpoint Demand. Isolate and depressurize the probe
chamber. Replace the probe. Pressurize the probe
chamber and turn the power back on.
MOISTURE INDICATOR
The moisture indicator consists of a small, clear,
polycarbonate filter filled with a color change silica gel. It
is located at the outlet of the dryer. When the dewpoint is
below -10°F, the desiccant is blue. When the dewpoint is
above -10°F, the desiccant is pink. A small amount of
sample air is required for operation.
FIGURE 7 — MOISTURE INDICATOR
OVER/HI TEMPERATURE ALARM
The Over/Hi Temperature Alarm consists of an alarm light
that illuminates when the temperature at the inlet of the
heater shell exceeds 200°F. Probable cause for this would
be reduced purge flow or no purge flow during the
heating cycle. Dry contacts are provided for remote
annunciation.
PANEL LIGHTS
The Panel Light option consists of four lights: Left Tower
Drying, Right Tower Drying, Left Tower Regenerating, and
Right Tower Regenerating. These lights are for dryer
sequence indication.
PLC CONTROLLER
PLC Controller is standard on PB series Blower Purge
dryers and with Pneumatech’s Pulse Purge Regeneration
option. It can also be added to control the operation of
standard regenerative dryers. Typically Square D or Allen
Bradley PLCs are used.
FILTER
HOUSING
SILICA GEL
