13
Box Temperature Control Settings
• There is an on board room thermostat on the
Beacon II board which can be adjusted to the
desired room temperature. The temperature
differential is 2°F.
Temperature Differential
When a system is in the cooling mode and
the box setpoint is 35°F, the system will
continue to cool until the box temperature
gets to 34°F. At this point the compressor
will pumpdown and shut off. The system will
restart cooling when the box temperature has
risen to 36°F.
It is important to note that Beacon II has
a minimum 2-minute “ON” time and a
Start-Up Operation
• Check all wiring connections to be sure they
are correct and tight.
• On condensing unit:
- Check the setting of Time Delay relay.
It should be set a one minute (the
second marker).
Refrigerant Charging
The cooler and freezer systems utilize refrigerant side
head pressure control. Charge each system by adding
an initial charge of 5 lbs. of R-448A refrigerant to the
liquid side of the receiver. This initial charge will allow
the system to start. With the system running, continue to
add refrigerant to the system until the sight glass is clear.
minimum 4-minute “OFF” time. This means
that the system will run in the cooling mode
a minimum of 2 minutes even if the setpoint
temperature is met. In applications where the
system is grossly oversized, the box tem-
perature could go below the differential tem-
perature before the system cycles off.
In the “OFF” cycle, the system will be off for a
minimum of 4 minutes even if the box tempera-
ture goes above the differential temperature
before cooling will be restarted.
• The on board room thermostat is factory set
at 35°F for air defrost systems and -10°F for
electric defrost systems.
Operate system until the cooler/freezer box achieves the
desired temperature. The sight glass should be clear with
no bubbles or ashing of refrigerant. Now the additional
charge for the ooded condenser is to be weighed into
each system in the amount as shown in Table 4.
- Check the Low Pressure switch
setting on freezer units. It must be set to
0 PSIG cutout, 10 PSIG cut-in to allow
positive start and operation, especially in
cold ambients. This can be changed to
a higher value in warmer climates.
On cooler units, the Low Pressure switch
has a xed setting and cannot be adjusted.
Beacon II Controller
Ambient Freezer Cooler Freezer Cooler
°F. ZF13 ZS13 ZF15 ZS13
80 3.0 4.0 6.0 4.0
70 2.0 3.0 5.0 3.0
60 1.0 3.0 3.0 3.0
50 1.0 2.0 2.0 2.0
40 1.0 1.0 1.0 1.0
30 0.5 1.0 1.0 1.0
20 0.5 0.5 0.5 0.5
10 0.5 0.5 0.5 0.5
0 0.5 0.5 0.5 0.5
MAC7X MAC8X
Table 4.
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