SERVICE AND TECHNICAL SUPPORT MANUAL
Gas Furnace: (F/G)9MVE
Specifications subject to change without notice.
440 04 4800 00
17
NOTE
:
1. Nominal 350 CFM/ton cooling airflow is delivered with SW1
−
5 and SW4
−
3 set to OFF.
Set both SW1
−
5 and SW4
−
3 to ON for +7% airflow (nominal 370 CFM/ton).
Set SW1
−
5 to ON and SW4
−
3 to OFF for +15% airflow (nominal 400 CFM/ton).
Set SW4
−
3 to ON and SW1
−
5 to OFF for
−
7% airflow (nominal 325 CFM/ton).
The above adjustments in airflow are subject to motor horspower range/capacity.
2. Maximum cooling airflow is achieved when switches SW2
−
1, SW2
−
2, SW2
−
3 and SW1
−
5 are set to ON, and SW4
−
3 is set to OFF.
3. All heating CFM’s are when low heat rise adjustment switch (SW1
−
3) and comfort/efficiency adjustment switch (SW1
−
4) are both set to OFF.
4. Ductwork must be sized for high
−
heating CFM within the operational range of ESP. Operation within the blank areas of the chart is not
recommended because high
−
heat operation will be above 1.0 ESP.
5. All airflows of 1880 CFM or less on 21” and 24.5” casing size furnaces are 5% less on side return only installations.
6. Airflows over 1800 CFM require bottom return, two
−
side return, or bottom and side return. A minimum filter size of 20” x 25” is required.
7. For upflow applications, air entering from one side into both the side of the furnace and a return air base counts as a side and bottom return.
8. Airflow not stable at this ESP.
SERVICE AND MAINTENANCE
PROCEDURES
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
The ability to properly perform maintenance on this
equipment requires certain knowledge, mechanical
skills, tools, and equipment. If you do not possess
these, do not attempt to perform any service and
maintenance on this equipment other than those
procedures recommended in the Owner’s Manual.
!
WARNING
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in
environmental pollution.
Remove and recycle all components or materials (i.e.
oil, refrigerant, control board, etc.) before unit final
disposal.
CAUTION
!
ELECTRICAL SHOCK, FIRE OR EXPLOSION
HAZARD
Failure to follow this warning could result in personal
injury or death, or property damage.
Before installing, modifying, or servicing system, main
electrical disconnect switch must be in the OFF
position and install a lockout tag. There may be more
than one disconnect switch. Lock out and tag switch
with a suitable warning label. Verify proper operation
after servicing.
!
WARNING
ELECTRICAL OPERATION HAZARD
Failure to follow this caution may result in improper
furnace operation or failure of furnace.
Label all wires prior to disconnection when servicing
controls. Wiring errors can cause improper and
dangerous operation.
CAUTION
!
General
These instructions are written as if the furnace is installed in an
upflow application. An upflow furnace application is where the
blower is located below the combustion and controls section of
the furnace, and conditioned air is discharged upward. Since
this furnace can be installed in any of the 4 positions shown in
, you must revise your orientation to component
location accordingly.
Figure 7
Multipoise Orientations
A93041
Electrical Controls and Wiring
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
There may be more than one electrical supply to the
furnace. Check accessories and cooling unit for
additional electrical supplies that must be shut off
during furnace servicing. Lock out and tag switch with
a suitable warning label.
!
WARNING
The electrical ground and polarity for 115
−
v wiring must be
properly maintained. Refer to
information and to
for furnace wiring information.
NOTE
: If the polarity is not correct, the STATUS LED on the
control will flash code 10 and prevent the furnace from heating.
The control system also requires an earth ground for proper
operation of the control and flame
−
sensing electrode.
The 24
−
v circuit contains an automotive
−
type, 3
−
amp. fuse
located on the control. (See
) Any shorts of the 24
−
v
wiring during installation, service, or maintenance will cause
this fuse to blow. If fuse replacement is required, use ONLY a
3
−
amp. fuse. The control LED display will be off when fuse
needs to be replaced.
