Defrost - Hussmann RL2W Installation & Operation Manual

P/N 3053328_C
If a leak is detected, follow store safety procedures.
It is the store's responsibility to have a written safety
procedure in place. The safety procedure must comply
with all applicable codes such as local fire department's
codes.
At minimum, the following actions are required:
• Immediately evacuate all persons from the store,
and contact the local fire department to advise them
that a propane leak has occurred.
• Call Hussmann and/or a qualified service agent
and inform them that a propane sensor has detected
the presence of propane.
• Do not let any persons back into the store until
the qualified service technician has arrived and that
technician advises that it is safe to return to the store.
• The propane gas used in the unit has no odor. The
lack of smell does not indicate a lack of escaped gas.
• A hand-held propane leak detector ("sniffer")
should be used before any repair and/or maintenance is
attempted. All repair parts must be identical models to
the ones they are replacing.
• No open flames, cigarettes or other possible
sources of ignition should be used inside the building
where the units are located until the qualified service
technician and/or local fire department determines
that all propane has been cleared from the area and
from the refrigeration systems.
Compressor Safety
The CoreLink Controller for these cases is
programmed with a compressor discharge safety
that cuts power to the compressor if the discharge
temperature exceeds 260°F to protect the compressor
in the event of high cooling water temperature or
other malfunctions. It uses a sensor that is located on
the compressor discharge line of each compressor, and
each compressor is controlled independently. This also
provides an alarm if the temperature is exceeded.
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A.
Sequence of Operation:
Refrigeration:
Compressor is cycling on discharge air temp. Fans stay
on when compressor cycles off.
Ice Cream application: Setpoint -10°F average
discharge air temp, 6°F differential
Medium Temp application: Setpoint 37°F average
discharge air temp, 6°F differential
Frozen food application: Setpoint -3°F average
discharge air temp, 6°F differential

DEFROST

Once per day
Low temperature:
Fans off during defrost
Defrost heaters on
Drain pan heater on
Compressor off
Medium temperature:
Fans on during defrost
No defrost or drain pan heaters
Compressor off
Defrost Termination
Termination by a sensor located on the left return
bend, center of the coil at 48°F . When defrost
terminates, the fans stay off until defrost termination
sensor reaches 20°F to provide a drip cycle (for low
temperature cases).
For cases with multiple compressors (4-door and 5-door):
Both compressors are tied together from one CoreLink
Controller, using the average of two discharge air
temperature sensors at the center of each coil (located
at the honeycomb).
Defrost is initiated and terminated for both units at
the same time, and terminates when both sensors reach
48 degrees. The controller incorporates a 5-second
delay between startup of the two compressors.
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Reach-In