Heatcraft Refrigeration Products 25001501 - Manual (Page 9)

BEACON CONTROLLER
9
Ambients below 50
°
F and above 10
°
F
At the initial application of power to the system, the compressor and the evaporator fans will be in a four
minute hold-off cycle and will not start immediately. When there is a call for cooling, the compressor starts
and the electric expansion valve (EEV) stays closed for 12 seconds. After 12 seconds the EEV goes to 7/8
open and the compressor is put in a four minute “hold-on” cycle. Superheat adjustments at two minute
intervals will then follow.
When the room thermostat setting becomes satisfied and if the compressor ran for at least four minutes, the
EEV will close and the compressor will pump-down and shut off. The evaporator fans will continue to run.
When the room sensor detects a rise in temperature of approximately 2
°
F and the compressor has been off
for at least four minutes, the EEV will open to it’s last position, 30 seconds before the compressor is started.
Ambients below 10
°
F
At the initial application of power to the system, the compressor and the evaporator fans, will be in a four
minute hold-off cycle and will not start immediately. When there is a call for cooling, the compressor starts
and the electric expansion valve (EEV) stays closed for 12 seconds. After 12 seconds the EEV goes to full
open, and the compressor is put in a four minute “hold-on” cycle.
When the room thermostat setting becomes satisfied and if the compressor ran for at least four minutes, the
EEV will close and the compressor will pump-down until the low pressure switch trips or one minutes has
elapsed. The evaporator fans will continue to run.
When the room sensor detects a rise in temperature of approximately 2
°
F and the compressor has been off
for at least four minutes, the EEV will open to it’s last position, 30 seconds before the compressor starts.
CONDENSER FAN CYCLING
Beacon condensing units will have pressure fan cycling and ambient fan cycling as standard. On one fan
condensing units, pressure fan cycling, with a setting of 150 psig cut-out and 200 psig cut-in is used. On two
fan condensing units, one fan will be controlled by an ambient switch, set at 50
°
F cut-out, and the other fan
will be controlled by the pressure fan cycling switch.