GMES8 GCES8 Installation Instructions

26
Installation’s seconds per cubic foot: 34 sec/ ft
3
Conversion Factor (hours to seconds): 3600 sec/hr
Input = (Htg. value x 3600) ÷ seconds per cubic foot
Input = (1,000 BTU/ ft
3
x 3600 sec/ hr) ÷ 34 sec/ ft
3
Input = 106,000 BTU/ hr
This measured input must not be greater than the input
indicated on the unit rating plate.
5. Turn ON gas and relight appliances turned off in step 1.
Ensure all the appliances are functioning properly and that
all pilot burners are operating.
TEM PERATURE RISE
Air temperature rise is the temperature difference between sup-
ply and return air. The proper amount of temperature rise is usu-
ally obtained when the unit is operated at the rated input with
the “as shipped” blower speed. If the correct amount of tem-
perature rise is not obtained, it may be necessary to change the
blower speed.
An incorrect temperature rise can cause condensing in or over-
heating of the heat exchanger. Determine and adjust the tempera-
ture rise as follows. The temperature rise must be within the range
specified on the rating plate or Specification Sheet applicable to
your model. (Please contact your dist ribut or or our website for the
applicable Specificat ion Sheet referred to in this manual.)
SUPPLY
AIR
RETURN
AIR
Temperature Rise Measurement
1. Operate furnace with burners firing approximately 15
minutes. Ensure all registers are open and all duct dampers
are in their final (fully or partially open) position.
2. Place thermometers in the return and supply ducts as close
to the furnace as possible. Thermometers must not be
influenced by radiant heat by being able to “ see” the heat
exchanger.
3. Subtract the return air temperature from the supply air
temperature to determine the air temperature rise. Allow
adequate time for thermometer readings to stabilize.
4. Adjust temperature rise by adjusting the circulator blower
speed. Increase blower speed to reduce temperature rise.
Decrease blower speed to increase temperature rise. Refer
to the following section for speed changing details.
CIRCULATOR BLOW ER SPEED ADJUSTM ENT
T O AVOID PERSONAL INJURY OR DEATH DUE TO ELECTRICAL SHOCK ,
TURN OFF POW ER TO THE FURNACE BEFORE CHANGING SPEED TAPS .
WARNING
Furnaces are equipped with EEM circulator blower motor. Refer
to the Blower Performance Data in the back of the manual for
proper selection of heating and cooling speeds. The cooling speed
is set at (T5), Heating at (T2) and circulation at (T1). These blower
speeds should be adjusted by the installer to match the installa-
tion requirements so as to provide the correct heating tempera-
ture rise and the correct cooling CFM .
To adjust the circulator blower speed, proceed as follows:
1. Turn OFF power to the furnace.
2. Select the heating and cooling blower speeds that match
the installation requirements from the airflow table in the
Specification Sheet applicable to your model. (Please
contact your dist ribut or or our w ebsite for the applicable
Specificat ion Sheet referred t o in this manual.)
3. Turn ON power to furnace.
4. Verify proper temperature rise as outlined in Temperature
Rise section.
O PERATIONAL C HECKS
WARNING
T
O AVOID PERSONAL INJURY OR DEATH, DO NOT REMOVE ANY INTERNAL
COMPARTMENT COVERS OR ATTEMPT ANY ADJUSTMENT.
E
LECTRICAL
COMPONENTS ARE CONTAINED IN BOTH COMPARTMENTS.
C
ONTACT A
QUALIFIED SERVICE AGENT AT ONCE IF AN ABNORMAL FLAME APPEARANCE
SHOULD DEVELOP.
CHECKING DUCT STATIC
Refer to your furnace rating plate for the maximum ESP (external
duct static) rating.
Total external static refers to everything external to the furnace
cabinet. Cooling coils, filters, ducts, grilles, registers must all be
considered when reading your total external static pressure. The
supply duct pressure must be read between the furnace and the
cooling coil. This reading is usually taken by removing the “A”
shaped block off plate from the end on the coil; drilling a test hole
in it and reinstalling the block off plate. Take a duct static reading
at the test hole. Tape up the test hole after your test is complete.
The negative pressure must be read between the filter and the
furnace blower.
Too much external static pressure will result in insufficient air
that can cause excessive temperature rise. This can cause limit
switch tripping and heat exchanger failure.