Installation Manual
38
• Outdoor fan and compressor are energized.
• Circulator blower is energized on the cool speed.
run their appropriate speeds, integrated control
module monitors safety circuits continuously.
call for cool.
• Outdoor fan and compressor are de-energized.
• Circulator blower continues running during a cool
The normal operational sequence in fan only mode is as follows:
• R and G thermostat contacts close, initiating a call
for fan.
• Integrated control module performs safety circuit
checks.
• Circulator blower is energized on heat speed.
• Circulator blower runs, integrated control module
monitors safety circuits continuously.
• R and G thermostat contacts open, completing the
call for fan.
• Circulator blower is de-energized.
• EAC terminal is de-energized.
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A number of safety circuits are employed to ensure safe and
proper furnace operation. These circuits serve to control any
potential safety hazards and serve as inputs in the monitoring
and diagnosis of abnormal function. These circuits are contin-
uously monitored during furnace operation by the integrated
control module.
The integrated control module is an electronic device which, if
a potential safety concern is detected, will take the necessary
The primary limit control is located on the partition panel
and monitors heat exchanger compartment temperatures. It
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ture-activated sensor. The limit guards against overheating
heat exchanger.
The auxiliary limit controls are located on or near the circula-
tor blower and monitors blower compartment temperatures.
conditioned air passing over the heat exchanger.
The rollout limit controls are mounted on the burner/manifold
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heat exchanger.
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heat exchanger via pressure taps located on the induced draft
blower and the coil front cover. These switches guard against
the heat exchanger and/or blocked condensate drain conditions.
components.
Use the following precautions during furnace installation and
servicing to protect the integrated control module from damage.
By putting the furnace, the control, and the person at the same
electrostatic potential, these steps will help avoid exposing
the integrated control module to electrostatic discharge. This
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integrated control module or any wire connected to the
control prior to discharging your body’s electrostatic
charge to ground.
furnace away from the control. Any tools held in a
person’s hand during grounding will be discharged.
3. Service integrated control module or connecting wiring
following the discharge process in step 2. Use caution
not to recharge your body with static electricity;
an ungrounded object, repeat step 2 before touching
control or wires.
installing the control on a furnace. Return any old or
new controls to their containers before touching any
ungrounded object.