Single temperature probe input.
One entrapment alarm push button
input
One door switch input
One refrigerant Leak Sensor input
Three defrost relay outputs.
Three fan control relay outputs
Three liquid solenoid relay outputs
Two levels of refrigerant leak alarm
relay outputs, 2 relays per alarm level. One Relay
for each level is silence-able and one is non
silence-able.
LEAD-LAG OPERATING MODE
The Lead-Lag system controls three
evaporators in the same cooling room. One system is
operated as the primary system while the other systems
are idle as the secondary system. The Control maintains
it room temperature utilizing the cooling capacity of
the master system. The WLL has the option of activating
the Secondary System should the space temperature
increase above a second cooling stage setpoint. The Control will automatically switch
the master system to secondary system to maintain the
equal run time on both systems. The Fans on each system
are ON while in cooling mode.
The Control alternates the systems after
three different situations:
The systems alternate when the
temperature within the room is met. The
evaporators operate in sequence. The "Primary System"
will become idle, the system idle for the longest
period of time will become primary.
Defrost. The systems will
switch to secondary immediately following a defrost
cycle.
Two hours of continuous operation.
Should the refrigeration system operate for a
continuous two hour period without the room
temperature satisfied, the controller will switch to
one of the idle systems and activate the system alarm.
FIFO (ROUND-ROBIN) OPERATING MODE
The Controller runs the evaporators
based on first-in, first-out mode (FIFO). The Controller
monitors the room temperature and maintains the room
temperature by utilizing the cooling capacity of the
evaporators. The evaporator liquid line which was turned
on first will be the one to be turned off when cooling
capacity requirement is reduced. This rotation scheme
equalizes the run time on each evaporator. This mode is
activated by menu selection and by shorting the inputs
at the MAX. COOLING FIFO activation input terminals.
DEFROST OPERATION
The entire system will defrost
simultaneously, eliminating conflicts between each system.
Defrost consists of four cycles: Pump down, Defrost,
Drip cycle, Fan on delay cycle.
All the cycle times can be adjusted. The
main defrost cycle on each evaporator will be terminated
by the closure of the temperature termination input
(T-stat) or by termination temperature probe reaching a
preset temperature.
ENTRAPMENT ALARM
User selectable option. When Entrapment
input is opened (Input is connected to a N.C. Entrapment
Push Button inside the cooling room), the Control will
enter into entrapment alarm mode immediately; the system
alarm relays are turned on, the front panel alarm light
are flashing and the buzzer is turned on. Entrapment
Alarm can only be reset manually by pressing the ALARM
RESET key.
DOOR OPEN ALARM
User selectable option. When door to the
room is opened (Door Alarm Input is closed), the Control
will start counting down the door alarm delay time.
After the delay time expired and the door is still
opened, the Control will enter into door alarm mode; the
system alarm relays are turned on, the front panel alarm
light are flashing and the buzzer is turned on. By
choice, the alarm can be reset when door is closed or
the alarm has to to be reset manually.
REFRIGERANT LEAK ALARM
User selectable option. The Control can
be used to monitor refrigerant leaks with the
installation of a Sherlock Refrigerant Sensor. There are
two alarm levels. Each alarm level has two alarm relay
outputs. One of the alarm outputs is silence-able. This
relay output can be connected to Audiovisual devices for
alarming. The non-silence-able relay output is connected
to EMS, BAS or local ALARM CENTER for remote and service
alarming. Alarm levels and alarm delays are adjustable.
