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SERVICE AND TECHNICAL SUPPORT MANUAL
Change the blower speed taps as required to maintain proper
temperature rise for Heating and Cooling as described above.
To change blower motor speed selections for heating mode,
remove blower motor lead from control HEAT terminal(s). (See
Figure 4) Select desired blower motor speed lead(s) from the
other motor leads and relocate it/them to HEAT (heating blower
tap) terminal(s). Reconnect original lead on SPARE terminal.
Adjust Blower Off Delay (Heat Mode)
If desired, the main blower off time delay period may be
lengthened or shortened when operating in the heating mode
to provide greater comfort. For position and location of jumpers
on control center. (See Figure 4 and Figure 15)
The blower off-delay has four adjustable settings from 108 sec
to 216 sec. (See Table 4) To change the blower off delay
setting, move the jumper from one set of pins on the control to
the pins used for the desired blower off delay. Factory blower
off-delay setting is 144 sec.
Table 4
Blower Off Delay Jumper Positions
PINS
1 AND 2
Control
90
(swtich setting)
Time (in sec.)
108
Adjust Cooling Airflow
The cooling airflow can be set from the remaining blower speed
taps. Refer to the Air Delivery Tables in these instructions.
CAUTION
!
FURNACE OVERHEATING HAZARD
Failure to follow this caution may result in reduced furnace
life.
Recheck temperature rise. It must be within limits specified
on the rating plate. Recommended operation is at the
mid--point of rise range or slightly above.
Adjust Thermostat Heat Anticipator
Mechanical thermostat: Set thermostat heat anticipator to
match the amp. draw of the electrical components in the R-W
circuit. Accurate amp. draw readings can be obtained at the
wires normally connected to thermostat sub-base terminals, R
and W. The thermostat anticipator should NOT be in the circuit
while measuring current.
1. Remove thermostat from sub-base or from wall.
2. Connect an amp. meter across the R and W sub-base
terminals or R and W wires at wall.
3. Record amp. draw across terminals when furnace is in
low heat and after blower starts.
4. Set heat anticipator on thermostat per thermostat
instructions and install on sub-base or wall.
5. Install blower access door.
Electronic thermostat: Set cycle rate for 3 cycles per hr.
440 04 4900 02
2 AND 3
3 AND 4
4 AND 5
120
150
180
144
180
216
Specifications subject to change without notice.
Figure 5
Amp. Draw Check with Ammeter
THERMOSTAT SUBBASE
TERMINALS WITH
THERMOSTAT REMOVED
(ANITICIPATOR, CLOCK, ETC.,
MUST BE OUT OF CIRCUIT.)
R Y W G
10 TURNS
FROM UNIT 24-V
CONTROL TERMINALS
5.0 AMPS ON AMMETER
EXAMPLE:
10 TURNS AROUND JAWS
Check Safety Controls
The flame sensor, gas valve, and pressure switch were all
checked in the Start−up procedure section as part of normal
operation.
1. Check Main Limit Switch
This control shuts off combustion system and energizes
air−circulating blower motor, if furnace overheats. By
using this method to check the temperature limit control,
it can be established that the limit is functioning properly
and that the limit will operate if there is a restricted
return−air supply or motor failure. If the limit control does
not function during this test, the cause must be
determined and corrected.
a. Run furnace for at least 5 minutes.
b. Gradually block off return air with a piece of
cardboard or sheet metal until the limit trips.
c. Unblock return air to permit normal circulation.
d. Burners will re−light when furnace cools down.
2. Check Pressure Switch(es)
This control proves operation of the draft inducer blower.
a. Turn off 220−V 50Hz power to furnace.
b. Disconnect inducer motor lead wires from wire
harness.
c. Turn on 220−V 50Hz power to furnace.
d. Set thermostat to "call for heat" and wait 1 minute.
When low pressure switch is functioning properly, hot
surface igniter should NOT glow and control
diagnostic light flashes a status code 3. If hot
surface igniter glows when inducer motor is
disconnected, shut down furnace immediately.
e. Determine reason low pressure switch did not
function properly and correct condition.
f. Turn off 220−V 50Hz power to furnace.
g. Reconnect inducer motor wires, replace door, and
turn on 220−V 50Hz power.
h. Blower will run for 108 seconds before beginning the
call for heat again.
i. Furnace should ignite normally.
Gas Furnace: F9MES
HOOK-AROUND
AMMETER
0.5 AMPS FOR THERMOSTAT
=
ANTICIPATOR SETTING
A96316
11
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