Heatcraft Refrigeration Products II - Manual (Page 21)

21
Beacon II Controller
STATUS INDICATOR LED (continued)
Status LED Display Description
• ERRORS E1 Room temperature sensor shorted, open
or not installed
E2 Defrost temperature sensor shorted, open
or not installed
E3 Suction temperature sensor shorted, open
or not installed
E4 Suction pressure transducer shorted, open
or not installed
E5 Outdoor temperature sensor shorted
E6 Low superheat during cooling
E7 Compressor shutdown (high or low
refrigerant pressure or low oil pressure)
E9 Multi-in/Multi-out wiring error
• OTHERS Coo Room Temperature sensor open or not
connected (Instead of displaying box
temperature)
Loc Board is locked. Settings cannot be changed
UnL Unlock the board settings
Low Ambient Operation
All units are shipped standard with head master valves. (Scroll compressor units have a 100 PSI head master
valve and all other systems have a 180 PSI head master valve.) Condensing units with
multiple condenser
fans will have one or more fans cycle on Pressure Fan Cycling switch.
An adjustable Time Delay relay, factory set at 1 minute, is wired across the Low Pressure Switch (LPS). In
cold ambient this allows time for the suction pressure to build up and prevent nuisance tripping of the LPS. In
warmer ambient this time delay relay can be adjusted to 0 minutes.
Pumpdown
At the end of each cooling cycle, when the box temperature is met, the Beacon system will pumpdown and
shut off the compressor.
To pumpdown, the EXV closes and the compressor runs until one of the following occurs:
• the low pressure switch opens
• the suction pressure at the evaporator is 4 psig
• a total of two minutes has elapsed.
When any of these three conditions occur the compressor will turn off and not restart until there is a call for
cooling.
Periodic pumpdown
While in the OFF cycle, if there isn’t a call for cooling (box set-point temperature is met) but:
• the evaporator suction pressure has risen to 10 psig
• the low pressure switch has closed.
The system will initiate a pumpdown. This periodic pumpdown will occur at 4 minute intervals when these two
conditions are met.