12
Beacon II Controller
Refrigerant Line Brazing (CAUTION)
The electric expansion valve and the suction temperature
sensor on the suction line are factory installed. Care must
be taken when brazing these lines at the evaporator.
Too high a temperature may destroy these components.
Heat absorbing compounds or “wet rags” must be used
when brazing the refrigerant line connections. The
suction line sensor should be removed before brazing.
Power Supply
The Beacon II board gets its 24 VAC power supply
from a transformer mounted in the electrical end of
each evaporator. On 208-230 volt systems, the multi-tap
transformer is shipped from our factory wired for 230
volts. If your supply voltage is 208 volt, you must change
to the 208 volt tap on the transformer.
VERY IMPORTANT: If the supply voltage to
the evaporator is 208 volts, the primary tap of the
transformer must be moved to the 208 volt tap.
This must be done for all the evaporators on that system.
If the 24 VAC power supply falls below 18 VAC, the
system may power down and shut off. When the power
supply is corrected to 24 VAC, the system will restart
after the four minute hold-off period and resume normal
operation.
Wiring
Wiring between the condensing unit and the unit
cooler(s) will be as follows
(see attached wiring diagrams):
• High voltage – There may be high voltage
on the defrost heater relay and the fan
relay. See unit cooler spec. plate for
ampacity.
•
Low voltage – 24V Class II control circuit. A
total of five low voltage leads are required to
connect the condensing unit to the evaporator
(see wiring diagram). Two of these leads are for
connecting the outdoor temperature sensor. The
other three leads are for connecting the
compressor relay, service relay and 24V
Common
inputs.
All 24 volt wiring must be run separate from the line
voltage wiring.
• Number of wires in low voltage wiring
bundles:
MAC to cooler evaporator - 5
MAC to freezer evaporator - 5
Cooler evaporator to Smart Controller - 6
Freezer evaporator to Smart Controller - 4
• Low voltage wiring must be 18 gauge
minimum. For low voltage wiring, maximum
distances
are:
Condensing unit to evaporator
500 ft.
Smart Controller to evaporator
1,000 ft.
• Alarm circuit – The onboard alarm (120VAC/2A)
is a dry set of NC contacts which closes to
indicate an alarm. The type and wiring for the
alarm is customer specified. Note that the alarm
circuit does not distinguish or indicate what has
caused the alarm.
• All wiring must comply with all applicable
codes and ordinances.
Note: All four corner brass spacers on the Beacon II board
should have sheet metal screws and they all should be
screwed in. By doing this, the board will have a ground
reference. Make sure the evaproator is grounded.
MAC7X MAC8X