
17
Electric Defrost Mode
When a defrost is initiated, the EEV closes, the system is allowed to
pumpdown and shut off. The evaporator fans are cycled off and the
defrost heaters are energized.
On multiple evaporator systems, all controllers must terminate their
defrost, either on temperature or fail-safe time, before the master
controller will end the defrost cycle.
There is a 2 minute condensate drain-down period after which the
system is started for a refreeze period. The evaporator fan stays
off (fan delay). The refreeze period will last until the evaporator
suction temperature is at 28°F or 3 minutes has elapsed. After
this sequence, the system is back in the refrigerating mode and
evaporators fans are now running.
Air Defrost Mode
The sequence is the same as for electric defrost except that there
are no heaters and the evaporator fans run continuously. If the air
defrost for motors are wired through the fan relay on the board, they
will remain energized during defrost mode.
Alarms
Beacon II provides a set of dry contacts for use in signaling an alarm.
These contacts can be connected to a light, a buzzer, a bell etc.,
which will be activated when an alarm condition occurs. When the
Beacon II is energized, the alarm contacts are OPENED. When an
alarm condition is detected, the contacts are CLOSED.
Conditions under which the alarm contacts will close are:
• High Box Temperature – LED Display:
A1
- Room temperature has exceeded
the Alarm High
ALH
value for the Alarm
time
ALt
programmed.
• Low Box Temperature - LED Display:
A 2
- Room temperature has dropped
below the Alarm Low
ALL
value for the
Alarm time
ALt,
programmed
Defrost / Alarms
Clearing Alarms
Alarms
A1
– High Box Temperature and
A 2
– Low Box Temperature
will clear automatically if the Box Temperature decreases or
increases to below or above the Alarm setpoint temperature. Placing
the system in the "
SERVICE MODE
" or turning off power will clear
the
A 3
Alarm. Replacing the Room Sensor, Suction Sensor or
Pressure Transducer will clear the
A 4
Alarm.
• System Start-up failure - LED Display:
A 3
- Compressor
pumps down and tries to restart after 4 minutes. After 4
unsuccessful attempts to restart, the alarm code
A 3
is
displayed. System continues trying to restart.
• Input Fault – LED Display:
A 4
- Box Temp., Suction Temp.,
Pressure Transducer open or not installed.
• Power failure – Loss of power to the Evaporator
A 1
High Box Temp
A 2
Low Box Temp
A 3
System Start-up failure
Compressor pumps down and tries to restart after 4
minutes
A 4
Input Fault
Box Temp., Suction Temp., Pressure Transducer open
or not installed
Power Failure
Alarm Codes
Содержание 25001401
Страница 29: ...29 Wiring...
Страница 31: ...31 Wiring TYPICAL EVAPORATOR WIRING TYPICAL ELECTRIC DEFROST WIRING DIAGRAM...
Страница 32: ...32 Wiring...