Displays And Alarms; Raise And Lower Buttons; Set Button; Hidden Button - AirTek SC Series Operator's Manual

DISPLAYS and ALARMS

1) DEW POINT CONTROLLER AND DISPLAY. Directly
controls dew point and provides constant digital
display of dew point. Factory set at 36ºF. During
ACTUAL display mode, displays the dew point tem-
perature from 20º to 99º F or -6º to 37º C. During DP
SET mode, the unit displays dew point set points from
34º to 50ºF in 1º steps, or 1º to 10ºC in 1/2 steps. (Note
that the ones digit decimal point is used to indicate 1/
2º when displaying set point in Celsius scale.) ºC LED-
indicates that the temperature is displayed in Celsius.
ºF LED – indicates that the temperature is displayed in
Fahrenheit. ACTUAL LED – indicates the display is in
ACTUAL mode. Display shows actual temperature
being measured by system. DP SET LED - Indicates
that the display is in programming mode during which
the set point can be changed and stored. The dew
point display also displays the unit error codes when
they occur. (see Diagnostic codes)
2) ON/OFF BUTTON FOR LOAD/NO LOAD MODE. LOAD/
NO LOAD LED - Indicates when the unit is operating in
the Load/No Load mode.
3) ON/OFF BUTTON FOR THERMAL BANK MODE. THER-
MAL BANK LED - Indicates when the unit is operating
in the thermal bank mode.
4) RAISE and LOWER BUTTONS. These are used to
adjust the set point values. The set point will change
once for each time pressed. If the button is pressed
and held, the set point will change one step per
second.
5) SET BUTTON. Toggles between Actual Display mode
and Set point Display mode. During the Set point
Display mode, the Raise and Lower keys are used to
select new set points which are stored in nonvolatile
memory when the mode is set back to ACTUAL. If no
keys are pressed within 15 seconds, the mode is
automatically set to "ACTUAL". This switch is also
used to select the temperature scale that the unit will
operate in. By pressing and holding for 5 seconds the
unit will toggle between the Fahrenheit and Celsius
scale.
6) HIDDEN BUTTON. Positioned in the bottom center of
the Dew Point window between the MODE keys. When
pressed, the display will show the external suction
temperature at the expansion bulb. It has no further
effect on operation. It may also be used for other
diagnostics and factory test purposes
7) POWER SAVER ACTIVE LED. Unit in mode of low
power consumption. Refrigeration system unloaded
or in thermal banking condition.
8) HIGH DEW POINT ALARM LED. Indicates that the unit is
in the High Dew Point condition. The high dew point
alarm light, with remote dry contacts, will activate when
the actual dew point is 15º F higher than the dew point
set point. Any diagnostic code will activate the high
dew point alarm immediately.
Airtek 4087 Walden Avenue, Lancaster, NY 14086 TEL: (716) 685-4040 FAX: (716) 685-1010 E-MAIL: airtek@airtek.com
9) DRAIN CONTROL SETTINGS. The DP5050-L series
control panel will operate by either a 'LEVEL FLOAT' or
'TIMED' interval. If the dryer is equipped with a Level
Float (electrical connections to terminal J9), the drain
will respond to the float signal on demand to operate
the drain. The duration that the drain valve is open, will
be the amount of time it takes for the fluid level to drop
and reset the float signal, plus, a pre-set time of a few
seconds thereafter. The drain valve will also operate
automatically once every 30 minutes (independent to
the float signal). The 30 minute timed interval setting
can be adjusted down to 1 minute or raised up to 60
minutes if desired. To adjust the drain 'Timed Interval'
setting, press the SET button twice (note that the Actual
and DP Set LED's will both extinguish). The value
indicated in the display will be the Timed Interval
setting. Use the UP or DOWN arrow to the desired
timing set point. Pressing the SET button again will
return the display to reading the dew point and the
'Actual' LED will once again illuminate.
10) DRAIN OPEN LED. Indicates that the drain valve is
open.
11) AIR INLET and AIR OUTLET PSI GAUGES. Indicates that
unit is pressurized. Unit must be depressurized and
bypassed before any service work is done on air
system. Excessive pressure drop (more than 5 PSIG)
across dryer indicates water may be freezing in the
evaporator.
12) HIGH AMBIENT TEMPERATURE DISPLAY AND LIGHT.
Should not be above 100ºF. High ambient temperature
can cause head pressure tripping of refrigeration
system and could result in non-warranty damage to
refrigeration compressor. Be sure dryer is installed
properly with adequate ventilation for air cooled units.
This display is used for water temperature in
watercooled units.
13) HIGH INLET TEMPERATURE DISPLAY AND LIGHT.
Should not be above 100ºF. High inlet air temperature
can cause overloading of dryer. If lit, check com-
pressed air aftercooler and/or oil cooler on air com-
pressor.
14) HIGH COALESCER PSID LIGHT (CT ONLY). Pressure
drop across coalescer element is too high. Should not
be above 9 PSIG. Excessive pressure drop could
cause mechanical failure of element resulting in flood
of oil, water and contaminants downstream of dryer.
Change element when necessary.
EXTERNAL SENSORS, CONTROLS and RELAYS
DRAIN RELAY (K1) – This onboard relay opens the drain
valve according to drain controls.
SUCTION RELAY (K2) – This onboard relay turns on
according to the mode and dew point conditions and opens
the suction or liquid line valve when active.
UNLOADER RELAY (K3) – This onboard relay turns on
according to the mode and dew point conditions and opens
the unloader valve when active.
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