507746-01
Issue 1821
Page 35 of 39
Indoor Blower Test
Indoor Blower Test Mode
Air handler control
in
Idle Mode
(No heating cooling or indoor
fan operation)
To enter indoor blower test mode
,
push and hold button next to
single character LED display until
—
(Solid bar) appears. Then,
release button.
Turn room thermostat to
OFF
(Solid bar) starts blinking .
Push and hold button until the
solid
A
symbol is displayed on the
single character LED display, then
release button.
Control will cycle the indoor blower motor for ten seconds at 70% of maximum air for selected capacity size unit.
Control will indoor blower test
mode.
Yes
No
A
-
-
Figure 26.
Operation
Cooling (Cooling Only or Heat Pump)
When the thermostat calls for cooling, 24 volts applied to
the blower time-delay relay coil. After a delay, the indoor
blower relay energizes. 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.
On heat pumps, circuit R and O energizes the reversing
valve, switching the valve to the cooling position. (The
reversing valve remains energized as long as the
thermostat selector switch is in the COOL position.)
At the completion of the cooling demand and after the
relay's timed delay, the compressor and outdoor fan will
cycle off.
Heating (Electric Heat Only)
When the thermostat calls for heat, the circuit between R
and W is completed, and the heat sequencer is energized.
A time delay follows before the heating elements and the
indoor blower motor come on. Units with a second heat
sequencer can be connected with the first sequencer to W
on the thermostat subbase, or they may also be connected
to a second stage on the subbase.
