8
Cleaning Condenser Coils:
It is recommended to inspect and clean the
condenser coil and fan blades every 3 months.
There are a variety of methods available for
cleaning the condenser coils. Keep in mind that
the debris is being drawn into the coil by the
condenser fan and the debris should be removed
in the opposite direction.
•
The simplest and preferred method would
involve the use of a vacuum cleaner to suck
the debris out of the coil from the outside
surface.
•
Another method is using compressed air to
blow dust from the coil. The debris should be
blown out from the inside surface of the coil.
WARNING
: When using compressed air, there
may be a cloud of dust released into the air
surrounding the machine.
It is recommended that the service person wear
proper protective equipment (i.e. safety glasses
and a dust mask) when performing coil cleanings.
Note:
DO NOT use any type of filter media in
front of the condenser coil to trap dust. Filter
testing has proven to create enough restriction of
air flow to reduce the efficiency of the coil’s heat
exchange.
Defrosting the Merchandiser:
Auto-Defrost models are equipped to be self-
defrosting and enter defrost mode once every four
hours automatically. During the defrost cycle, the
power to the refrigeration system will be
automatically re-directed to the defrost circuit.
This will shut down power to the condensing unit
and evaporator fan motors and also send power to
a heat element that is attached to the surface of the
evaporator coil. The heat generated by the
element will melt the ice build-up on the
evaporator coil and the resulting melt water will
drain through a tube out of the back wall of the
merchandiser.
On outdoor cabinet models, the melt water will
exit the drain tube directly to the ground.
On indoor cabinet models, the consumer needs to
install the condensate evaporator heater assembly
(described in the
Installation
section of this
manual) onto the exterior back wall of the cabinet.
The melt water from the defrost cycle will drain
into a catch pan where it will then be heated to the
point of evaporation. The function of the
condensate evaporator’s heat element should be
checked routinely. Failure of the element could
result in an over-flow condition for the assembly’s
drain pan. A simple check of the heater would be
a touch test of the surface temperature of the
assembly’s housing. The condensate evaporator’s
heat element is energized continuously so the
surface of the housing should always be hot to the
touch. If testing the heat element with a meter, the
element can be unplugged from its’ power source
and a resistance reading can be taken through the
plug’s bladed terminals. The condensate heater is
rated to generate 125 watts of power, which
translates to approximately 106 ohms of
resistance.
Auto-Defrost Electronic Control:
The control is factory set for a 24 minute defrost
cycle to occur at 4-hour intervals. Like a
mechanical defrost timer, the electronic control
will switch power from run mode (condensing
unit and evaporator fans) to defrost mode (defrost
heat element). Whereas a mechanical timer
operates strictly on a timed cycle, the duration of
the electronic control’s defrost cycle is controlled
by the temperature at the sensor probe “P2.” If the
temperature at this probe reaches 60-65°F prior to
the 24-minute timed cycle ending, the control will
override the timed cycle and immediately switch
power from the defrost mode to a drip time then
standard run mode. If temperature is not reached
at probe “P2,” the defrost cycle will continue for
the entire 24- minute programmed cycle prior to
returning to run mode. Energizing the defrost
circuit in the electronic control can be verified
with the illumination of the “melting snowflake”
and the letters “dE” appearing on the control’s
display.
