Important Operating Instructions; System Operation; Cooling Operation; Auto Mode Operation - Lennox MS8 Manual

Important Operating Instructions

To ensure comfort, make sure that temperature selection has been
properly set at the remote control.
To ensure efficient operation, do not block air intake or outlet at either
the indoor or outdoor unit.
Do not stand on outdoor unit or store items on top of unit.
Make sure that indoor unit directional louver is properly adjusted.

System Operation

Cooling Operation

In the cooling mode, the indoor coil absorbs the
heat from the room and transfers it to the outdoor
coil where it is discharged. The system cooling
capacity is affected by the outdoor ambient tem­
perature. The indoor fan operates continuously in
the COOL mode. The indoor unit directional lou­
ver is fixed in an upward position.
In 115V systems, when the outdoor ambient tem­
perature falls below 32°F (0°C), the indoor unit
control locks out operation to protect the system.
The cooling mode operating range of the outdoor
unit in these systems is typically from 41°F (5°C)
to 115°F (46°C).
In 208/230V systems, the cooling mode operating
range of the outdoor unit is typically from 23°F
(-5°C) to 118°F (48°C).
Heating Operation
The refrigerant flow is reversed during the heating
cycle. In this case, the outdoor coil absorbs the
heat from outside and transfers it to the indoor coil
where it is discharged into the room. The system
heating capacity is also limited by the available
heat in the outdoor ambient air.
In the HEAT mode, the indoor fan will remain OFF
for two minutes in the following instances:
D at the beginning of each heating cycle,
D after a defrost cycle has ended,
In the heating mode, the indoor blower will contin­
ue to operate for 60 seconds after the outdoor unit
has shut off. The indoor unit directional louver is
fixed in a downward position.
In climates with very low winter temperatures, it
may be necessary to supplement heating by addi­
tional means (space heater, fireplace, etc.).
In heating mode, the operating range of the out­
door unit is typically from 05°F (-15°C) to 86°F
(30°C).
IMPORTANT

AUTO Mode Operation

When the system is set to operate in AUTO mode,
the indoor and outdoor units work together to
meet a series of preset demands. The remote
control temperature setpoint and fan operation
functions are not adjustable in the AUTO mode.
In AUTO mode, if the indoor ambient temperature
is greater than 77°F (25°C), the unit will operate
in the cooling mode. The outdoor unit will run until
the indoor ambient temperature reaches 75°F
(24°C). At this point, the outdoor unit compressor
and outdoor fan will operate for another 60 sec­
onds, then they will both turn off. The indoor fan
will run continuously at a speed determined by the
indoor ambient temperature. During AUTO cool­
ing operation, the indoor unit directional louver is
fixed in an upward position.
Heat Pump Systems Only -- In AUTO mode, if the
indoor ambient temperature is less than 68°F
(20°C), the unit will run in heating mode. The out­
door unit will run until the indoor ambient temper­
ature reaches 69°F (21°C). At this point, the out­
door unit compressor and fan will operate for
another 60 seconds, then they will both turn off.
The indoor fan will run continuously at a speed
determined by the indoor ambient temperature.
During AUTO heating operation, the indoor unit
directional louver is fixed in a downward position.
FAN Mode Operation
When the system is set to operate in FAN mode,
the indoor fan runs continuously in AUTO, low,
medium or high speed. The outdoor unit is off. In
AUTO fan mode, the fan speed is determined by
the indoor ambient air temperature.
DEHUMIDIFICATION Mode Operation
When the system is set to operate in DEHUMID­
IFICATION mode, the indoor fan runs continu­
ously in low speed.
4