507746-01
Issue 1821
Page 36 of 39
Heating (Heat Pump)
When the thermostat calls for heating, 24 volts is applied to
the blower time-delay relay coil. After a delay, the normally
open contacts close, causing the indoor blower motor to
operate. The circuit between R and Y is completed, closing
the circuit to the contactor in the outdoor unit, starting
the compressor and outdoor fan motor. Circuit R and G
energizes the blower relay, starting the indoor blower
motor.
If the room temperature continues to fall, the circuit between
R and W1 is completed by the second-stage heat room
thermostat. Circuit R-W1 energizes a heat sequencer. The
completed circuit energizes supplemental electric heat (if
applicable). If the unit includes a second heat sequencer,
it can be connected with the first sequencer to W1 on
the thermostat. The second heat sequencer may also be
connected to second-stage heating (W2) on the thermostat
subbase.
Emergency Heat (Heating Heat Pump)
If the selector switch on the thermostat is set to the
emergency heat position, the heat pump will be locked
out of the heating circuit, and all heating demand will
be satisfied by the electric heat (if applicable). A jumper
should be placed between W2 and E on the thermostat
subbase so that the electric heat control will transfer to the
first-stage heat on the thermostat. This will allow the indoor
blower to cycle on and off with the electric heat when the
fan switch is in the AUTO position.
Repairing or Replacing Cabinet Insulation
DAMAGED INSULATION MUST BE REPAIRED OR
REPLACED
before the unit is put back into operation.
Insulation loses its insulating value when wet, damaged,
separated or torn.
IMPORTANT
Matte- or foil-faced insulation is installed in indoor equipment
to provide a barrier between outside air conditions
(surrounding ambient temperature and humidity) and the
varying conditions inside the unit. If the insulation barrier is
damaged (wet, ripped, torn or separated from the cabinet
walls), the surrounding ambient air will affect the inside
surface temperature of the cabinet. The temperature/
humidity difference between the inside and outside of the
cabinet can cause condensation on the inside or outside
of the cabinet which leads to sheet metal corrosion and
subsequently, component failure.
Repairing Damaged Insulation
Areas of condensation on the cabinet surface are an
indication that the insulation is in need of repair.
If the insulation in need of repair is otherwise in good
condition, the insulation should be cut in an X pattern,
peeled open, glued with an appropriate all-purpose glue
and placed back against the cabinet surface, being careful
to not overly compress the insulation so the insulation can
retain its original thickness. If such repair is not possible,
replace the insulation. If using foil-faced insulation, any
cut, tear, or separations in the insulation surface must be
taped with a similar foil-faced tape.
1. CUT INSULATION IN X PATTERN
2. APPLY GLUE
3. PRESS GLUED TABS AGAINST CABINET
GLUE -make sure there is
full coverage of glue on the
metal or insulation so there
are no areas where air
pockets may form which
can lead to sweating.
Figure 27. Repairing Insulation
Electric Shock Hazard.
Can cause injury or death.
Foil-faced insulation has conductive characteristics
similar to metal. Be sure there are no electrical
connections within a ½” of the insulation. If the foil-faced
insulation comes in contact with electrical voltage, the
foil could provide a path for current to pass through to
the outer metal cabinet. While the current produced
may not be enough to trip existing electrical safety
devices (e.g. fuses or circuit breakers), the current can
be enough to cause an electric shock hazard that could
cause personal injury or death.
WARNING
Homeowner Maintenance
Do not operate system without a filter. A filter is required
to protect the coil, blower, and internal parts from
excessive dirt and dust. The filter is placed in the return
duct by the installer.
IMPORTANT
•
Inspect air filters at least once a month and replace or
clean as required. Dirty filters are the most common
cause of inadequate heating or cooling performance.
