McCall MCCR1-G - Manual (Page 10)

10
McCall Series I Reach-In Manual
The electronic temperature control constantly monitors box
temperature as well as evaporator coil temperature to maintain
consistent product temperatures. The control also sends
temperature readings to the digital temperature display. The
control circuits continually self-check and if an error occurs,
the digital display will switch from temperature read-out to
error read-out, i.e. E1. Even when an error is displayed, the
refrigeration and controls system should continue to function,
however not at optimal performance. Whenever the display has
an error read-out, McCall Service should be contacted.
At initial start-up or anytime power is disconnected, then
reconnected to the unit, the control will delay all operations for
a short time (up to 10 minutes.) While in this delay period, the
control initializes the control parameters and confirms that the
temperature sensors and circuits are operational. The digital
temperature display will not display temperature OR errors until
the self-check is complete and the control has switched on the
evaporator fan motor, compressor and condenser fan motor.
REGARDING FREEZERS: After initializing, the control
will immediately enter a DEFROST mode and the
display will read DEF. The compressor and condenser
fan as well as the evaporator fan will remain off until
initialization defrost is complete. This initial defrost
cycle may take up to 15 minutes to complete, at which
time the freezing cycle will begin. The display will
continue to read DEF for an additional 30 minutes
before displaying temperature.
The control is located in the control box in the top of the unit
behind the hinged louvered front panel. Refrigerators are factory
set at mid-range to maintain about 38ºF (3ºC) box temperature.
Freezers are factory set at mid-range to maintain about 3ºF
(-18ºC) box temperature. To adjust for colder temperatures,
turn the knob clockwise. For warmer temperatures, turn the
knob counter-clockwise. Turn the knob fully counter-clockwise
to turn the refrigeration system off. Never turn the knob more
than 1 dial number and always allow 8 hours for temperature
stabilization before making any additional adjustments.
Refrigerator:
Whenever the refrigerator is plugged in, and the control has
completed initializing, the evaporator fans will run continuously
and the optional digital temperature will display box temperature
in degrees F. The temperature control will cycle the compressor
and condenser fan motor to maintain box temperature at the
control setting.
Refrigerator Defrost
The temperature control also monitors the evaporator temperature
and will turn off the compressor and condenser fan motor when
needed to allow accumulated frost on the evaporator to clear.
During this defrost cycle, the digital temperature display will
read dEF. After the defrost cycle is complete, the temperature
control will return to a normal cooling cycle, but the display
will continue to read dEF until the evaporator returns to normal
cooling temperatures (up to 15 minutes).
Energy Saver Switch
The energy saver switch is a rocker switch located next to the
thermostat knob. The normal operating position for this switch
is the OFF or “0” position. If excessive condensation is observed
on the door opening, flip the energy saver switch to the ON or “-”
position, (red portion of the rocker switch will be visible).
Freezer:
Whenever the freezer is plugged in, and the control has completed
initializing including the initial defrost cycle, the evaporator
fans will run continuously (except during a defrost cycle) and
the digital temperature display will display box temperature in
degrees F. The temperature control will cycle the compressor
and condenser fan motor to maintain box temperature at the
control setting.
Freezer Automatic Defrost
The control also monitors compressor total running time and
will enter a defrost cycle after total compressor running time is
greater than 4-hours since the last defrost cycle OR if evaporator
coil temperature drops below -34ºF (-37ºC) (indicating excessive
frost on the coil.)
Freezer Manual Defrost
If a manual defrost is desired, simply unplug the unit for several
seconds, then plug unit back in. This will cause the control to
re-initialize and then enter a defrost cycle.
When the control enters the defrost mode, it switches off the
evaporator fan motor, compressor and condenser fan motor,
and switches on the defrost heater to warm the evaporator
coil. Thereby melting all frost accumulated during the previous
refrigeration cycle. The digital temperature display will now read
dEF. The control will continue the defrost cycle for a MINIMUM
of 8 minutes and a MAXIMUM of 30 minutes depending on the
amount of frost accumulated on the evaporator coil.
After the defrost cycle is complete, the control returns to a normal
refrigeration cycle, however the evaporator fan motor will not
switch on for 2 minutes AFTER the compressor and condenser
fan motor have begun operating. The digital temperature display
will continue to read dEF until the evaporator has returned to
normal freezing temperatures (up to 30 minutes).
Dual Temperature Refrigerator/Freezer Cabinets
These units combine both a refrigerator compartment and a
freezer compartment in the same cabinet. Each compartment
has its own separate refrigeration unit.
Electronic Temperature Control Operation