GMEC96 Installation Manual

50

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
precautions and provide diagnostic information through an LED.

The primary limit control is located on the partition panel
and monitors heat exchanger compartment temperatures.
It is a normally-closed (electrically), automatic reset,
temperature-activated sensor. The limit guards against

over the heat exchanger.

The auxiliary limit controls are located on or near the circula-
tor blower and monitors blower compartment temperatures.
They are a normally-closed (electrically), manual-reset sensors.

conditioned air passing over the heat exchanger.

The rollout limit controls are mounted on the burner/manifold
        -
ly-closed (electrically), manual-reset sensors. These limits

heat exchanger.

The pressure switches are normally-open (closed during oper-
ation) negative air pressure-activated switches. They monitor
        
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.


        


Low stage cooling Mode sequence:
On a call for lo cool, the YLO and G thermostat
contacts close signaling the control module.
 
The compressor and condenser fan are energized.
The compressor is connected to the YLO terminal
of the control module.
The circulator fan is energized at lo cool speed after
a cool on delay. The electronic air cleaner will also
be energized.
 

begins.
 
period, the cool circulator and air cleaner relay are
de-energized.
Single cooling stage thermostat or 2
nd
stage cooling
Mode sequence:
On a call for cool, the Y and G thermostat contacts
close signaling the control module.
 
The compressor and condenser fan are energized.
The circulator fan is energized at cool speed after
a cool on delay. The electronic air cleaner will also
be energized.
 

Following the 45 second fan off delay period,
the cool circulator and air cleaner relay are de-
energized.
 If a call for both YLO and Y are present, Y will have
priority.

MANUAL FAN ON:
Call for continuous fan (24 volts on the furnace “G”
terminal.)
The LED will display rapid “GREEN”.
The circulator blower and the electronic air cleaner
terminal are energized.

-
ment door installed. Flames should be stable, quiet, soft, and
blue (dust may cause orange tips but they must not be yellow).
Flames should extend directly outward from the burners without

