Heatcraft BOHN MAC8X User Manual

11
Installation Tips
Use a minimum 18 gauge wire for all low voltage
connections.
• The Beacon II board get 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.
• Refer to wiring schematic shipped on units for
wiring.
• Evaporators are shipped from our factory with
a preset box setpoint temperature of 35°F for
air defrost and -10°F for electric defrost. If your
box setpoint temperature requirements are different
this must be set using directions outlined
under “Room Temperature Control”.
• The suction line temperature sensor MUST be
removed from the suction line before brazing the
suction tubing. The sensor MUST then be reinstalled
on the suction line after brazing is completed and the
tubing has cooled. Insulate when nished.
• The low pressure switch time delay relay, located
in the condensing unit, must be set to 1 minute.
• Some systems may require the crankcase heater
to be energized 24 hours prior to start-up. The
Beacon II should be de-energized for this period
by placing it in the SERVICE MODE. This is done
by pressing the “FORCE SERVICE” button twice.
To start the system cooling, press the “CLEAR”
button.
• Room sensors must be left connected on ALL
evaporators.
• A pressure transducer is installed on the
evaporator. Do not leak test system above 150
PSI or damage to transducer could occur.
• Refer to the Beacon II Smart Controller
Installation Manual, shipped with the Beacon II
Smart Controller, for installation, programming
and monitoring information.
Condensing Unit
The condensing unit control panel contains the relays,
contactors, and a terminal block which is appropriately
marked to match the low voltage wiring connections.
A sensor for outdoor air temperature measurement is
installed on the condensing unit.
Condensing unit must be installed using proper
refrigeration practices and codes. Make sure there is good
airow and good clearances around unit. See Figure 4,
page 5.
Evaporator Unit
The evaporator contains the BEACON II controller(s),
electric expansion valve(s), pressure transducer,
distributor(s), orice(s), transformer and three sensors.
These components are all factory mounted and wired. The
three sensors are factory mounted and provide input to the
controller from the following: defrost temp., suction temp.,
room temp.
Each evaporator unit must be installed using proper
refrigeration practices and codes. Make sure the piping is
correctly sized and properly routed. Liquid and suction
lines MUST be insulated. There must also be good
clearance around the unit.
See Figure 3, page 4.
Beacon II Controller

Heatcraft BOHN MAC8X Specifications

General

Brand	Heatcraft
Model	BOHN MAC8X
Category	Heat Pump
Language	English