Page 10 of 14
507860-01
Issue 1927
Maintenance
Disconnect all electrical power to the unit before
conducting any maintenance procedures. Failure to
disconnect the power could result in personal injury or
death.
WARNING
Periodic inspection and maintenance normally consists of
changing or cleaning filters and (under some conditions)
cleaning the coils.
Filter
Inspect the filter once a month. Replace disposable filter or
clean the washable filter as necessary (a minimum of three
times each heating or cooling season is recommended).
Do not replace washable filter with a disposable filter
unless an installation was made in which the filter was
mounted exterior to the unit (see
Air Filter
section).
To clean the washable filter, shake filter to remove excess
dirt and/or use a vacuum cleaner. Wash filter in soap or
detergent water and replace after filter is dry. It is not
necessary to oil the filter after washing.
Motors
The indoor and outdoor fan motors are permanently
lubricated and require no maintenance.
Outdoor Coil
Foreign material should not be allowed to accumulate on
the outdoor coil surface or other parts in the air circuit.
Cleaning should be as often as necessary to keep the coil
clean. To clean the coil, remove the lower access panel
and blow out debris by using compressed air or water.
Be
sure power to unit is shut off before using water to
clean the coil.
Care should be used when cleaning the coils so that
the coil fins are not damaged.
Outdoor Base Drain
Foreign material should not be allowed to clog the drain
hole. Inspect and clear drain opening.
Operation
Sequence of Operation
Upon initial “power up” to unit, there is a 3-minute time delay
to the compressor contactor (R to Y). Any 24V interrupt (R,
C) to the defrost control will initiate the 3-minute delay to
the contactor.
Cooling
When the thermostat is in the cooling mode, the O circuit
is powered which energizes the reversing valve. Upon
cooling demand, the thermostat closes circuit R to Y and
G. Closing R to Y closes the unit contactor, starting the
compressor and outdoor fan, and signaling the indoor
blower to run at cooling speed. Upon satisfying cooling
demand, the thermostat will open the above circuits and
open the main contactor, stopping the compressor and
outdoor fan. The unit is equipped with a blower OFF delay;
the blower will continue to operate for a fixed 90 seconds
after the thermostat is satisfied.
Heating
Upon heating demand, the thermostat closes circuit R to
W. On units supplied with heat strips, the sequencers are
then energized and bring on the auxiliary electric heat.
Units with no factory heat installed contain an auxiliary
heat relay that will close, energizing the 24VAC output.
This output can be used to control (not power) an auxiliary
heat source. The W signal from the thermostat brings the
indoor blower on at electric heat speed. Upon satisfying
heating demand, the thermostat opens the above circuits
and stops unit operation.
The unit is equipped with a blower OFF delay; the blower
will continue to operate for a fixed 120 seconds (electric
heat) after the thermostat is satisfied.
NOTE:
The 7.2 and 10 kW heats strips offer a W1 and
W2 thermostat connection. Taking advantage of the two
heat strip circuits requires a 3-stage thermostat (Y for heat
pump, W1 for electric heat stage 1, and W2 for electric
heat stage 2). If a 2-stage thermostat is used, “pigtail” W1
and W2 wires together when connecting the thermostat
wires at the unit.