DEFROST CONTROL FOR HEATPUMP UNIT
The
Skil–Aire
heat pump utilizes a defrost system controlled by a temperature sensing
device. The defrost cycle initiates when the bulb attached to the outdoor coil senses a
temperature of 30 F or less. This means that the unit (when in the heating cycle) will go into
a defrost cycle only id the outdoor coil is cold enough to accumulate frost. The defrost cycle
ends when the outdoor coil temperature rises to 80 F.
?
DE-HUMIDIFICATION AND REHEAT
(Wall Mounted thermostat)
Upon an increase in humidity beyond the set point on the wall mounted de-humidistat the
cooling cycle is energized. The unit will remain in cooling until the humidity level in the room
reaches the set point on the de-humidistat. If the room temperature falls below the set point
on the room thermostat the reheat coil will energize to offset the cooling effect of the de-
humidification cycle. There must be at least a low load in the room to maintain room
temperature.
(Unit Mounted thermostat)
On units with a unit mounted thermostat the reheat is controlled by the same thermostat that
controls the cooling cycle. Reheat can not be energized except when there is a call for de-
humidification which functions the same as the units with wall mounted controls.
SYSTEM SAFETIES
The unit has several inherent safety devices. High and Low pressure switches are an
integral part of the refrigeration system. Should an unsafe high and or low-pressure condition
exist the appropriate safety device will trip. Condensate overflow switches are installed on
the drain pan of each unit. There are two switches and should the condensate level rise to
an unsafe level the switches will cause the unit to shut down operation. This is accomplished
by interrupting the low voltage power supply from the 24-volt transformer. Both compressor
and fan motor have an internal automatic reset safety, which is the thermal type.
MAINTENANCE
Filter Changes:
The unit is supplied with a 20 x 20 x 1 disposable filter. Access to
the filter is through the hinged return air grille. This filter should be
changed a minimum of four times per year. A higher frequency of
filter changes may be necessary depending on the area where the
unit is installed.
Fan motor Lubrication:
The evaporator fan motor should be oiled once per year using a
SAE#10 or SAE#20 non-detergent oil. There are oil ports at each
end of the motor.
Evap. and Cond. Coil:
Clean both coils with a stiff brush. Be careful of the coil fins due
to the fact that they are razor sharp. After brushing use a vacuum
or compressed air to clean away brushed off dirt.
Remote Condenser Coil: Clean coil as stated above or use low pressurized water or steam.
Condensate pan & Drain: Check and clean on a bi-monthly basis.
Humidifier:
Check canister on a bi-monthly basis for material builds up,
replaces as required.
