12
Nirvana Cycling Refrigerated Dryer Models 3250-8000
ingersollrandproducts.com
7.0 PRINCIPLES OF OPERATION
7.6.5
ALARMS AND THEIR FUNCTIONS
There are several alarms detected by the Microprocessor
Control to alert the user of an out of tolerance condition. Once
each alarm is detected, a description of the alarm will appear
in the screen and the remote alarm contact will close. Note
that during the alarm condition, the SELECT DISPLAY button
may be depressed to scroll through the available parameters.
After approximately 30 seconds, the alarm screen will
reappear, provided the alarm condition persists.
The alarm names and a brief description of each are described in
detail below. Note that some alarms will enunciate only after a
prescribed alarm delay.
HIGH TEMPERATURE ALARM (HITEMP ALARM)
When the thermal mass (glycol) temperature reaches the factory alarm
set point, after an alarm delay, the module’s alarm will be activated.
This alarm condition that may not necessarily damage the dryer when
subjected to long-term exposure. It may, however, have a significant
impact on downstream processes and thus should be investigated
upon detection. Note that this alarm will not shut down the dryer. This
alarm will reset automatically once the alarm condition is rectified.
LOW TEMPERATURE SAFETY ALARM (LOWTEMP ALARM)
If the dryer chiller temperature falls to or below the factory set point and
remains at or below this set point for the factory delay time, the alarm
routine will activate. This alarm condition may cause damage to the
dryer when subjected to continuous or long-term exposure. Note that
this alarm will shut down the dryer after a response time delay. This
alarm will activate the remote alarm contact and reset automatically
once the alarm condition is rectified.
HIGH PRESSURE CUTOUT ALARM (HPCO ALARM)
If the discharge pressure of the refrigerant is determined to be above
the set point, the alarm routine will activate. This alarm condition may
cause damage to the dryer when subjected to continuous or long-term
exposure. Note that this alarm will shut down the dryer after a
response time delay. The operator must depress the RESET button in
order to clear the alarm and restart the refrigeration system.
LOW PRESSURE CUTOUT ALARM (LPCO ALARM)
If the suction pressure of the refrigerant is determined to be below the set
point of the LPCO alarm, the Microprocessor Control alarm routine will
activate. This alarm condition may cause damage to the dryer when
subjected to continuous or long-term exposure. Note that once cleared,
the compressor will restart automatically. However, if two successive low-
pressure conditions are determined, this alarm will shut down the dryer
after a response time delay and will display the alarm condition. The
operator must depress the RESET button in order to reinstate the
compressor.
Alarm
Display
Alarm Set Point
HIGH PRESSURE CUTOUT
HI PRESS CO
See Table 1
LOW PRESSURE CUTOUT
LO PRESS CO
See Table 1
HIGH TEMPERATURE ALARM
HITEMP ALRM
55 °F
LOW TEMPERATURE ALARM
LOTEMP ALRM
30 °F
TABLE - 1
7.6.6
START MODES
Ingersoll Rand dryers are capable of starting in several start
modes.
7.6.6.1 AUTO
Mode
After power is supplied to the dryer and once the Crankcase
Heater Delay has timed out, the Microprocessor Control will
display the ASC delay, followed by the “PRESS ON BUTTON”
display. Provided the thermal mass temperature is above the
set point, turning the Dryer Operation Switch on the Main
Power Enclosure to the “AUTO” position will start all the
refrigeration systems simultaneously.
7.6.6.2
REMOTE Mode
This mode of operation allows the user to turn the dryer on
and off remotely and requires the installation of a customer-
supplied switch (see Wiring Diagram). For this mode, the
Dryer Operation Switch is placed in the REMOTE position.
With power applied to the dryer and once the ASC and
Crankcase Heater Delays have timed out, the dryer will start
once the remote switch is closed provided the chiller
temperature is above the set point.In addition, this mode of
operation still permits manual control of the dryer via the
Microprocessor Control’s ON & OFF pushbuttons. Note that
the switch must be rated for 120VAC service.
7.6.6.3
MANUAL Mode
After power is supplied to the dryer and once the Crankcase
Heater Delay has timed out, the Microprocessor Control will
display the ASC delay, followed by the “PRESS ON BUTTON”
display on each module. In this mode, the user must depress
the ON button on each Microprocessor Control to operate
each refrigeration system. Note that regardless of the position
of the Dryer Operation Switch, the user may operate each
module individually by depressing the local “ON & OFF”
buttons of each module’s Microprocessor Controller.
Parameter
R-404A
R-407C
FAN 1 ON
275 psig
235 psig
FAN 1 OFF
195 psig
195 psig
FAN 2 ON
335 psig
265 psig
FAN 2 OFF
235 psig
210 psig
HPCO (Air Cooled)
450 psig
400 psig
HPCO (Water Cooled)
320 psig
320 psig
LPCO
20 psig
20 psig
