Heatcraft Refrigeration Products BEACON II H-IM-79E, Installation And Operation Manual

Page: 7 / 36

7
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
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 temperature could go
below the differential temperature before the
system cycles off.
In the “
OFF
” cycle the system will be off for
a minimum of 4 minutes even if the
box temperature 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 system.
Box Temp Control Settings
Leak Testing
After all lines are connected, the entire system must be
leak tested. The complete system should be pressurized
to not more than 150 psig with refrigerant and dry
nitrogen. The use of an electronic type leak detector is
highly recommended because of its greater sensitivity
to small leaks. As a further check it is recommended
that this pressure be held for a minimum of 12 hours
and then rechecked. For a satisfactory installation, the
system must be leak tight.
Refrigerant Charging
Beacon II systems are shipped standard with a
head
master valve (scroll compressor models have a 100 PSI
head master valve. All other models have a 180 PSI head
master valve). The maximum system refrigerant capacity
is the receiver capacity as listed in the sales literature
plus the liquid line capacity. Do not add more refrigerant
to the system than 90% of the receiver capacity.