ICP F9MXT0401410A Service and technical support manual - Caution
SERVICE AND TECHNICAL SUPPORT MANUAL
Gas Furnace: (F/G)9MXT
Specifications subject to change without notice.
10
440 04 4321 04
Table 3 (Cont.)
Orifice Size and Manifold Pressure (in. w.c.) for Gas Input Rate
S
A
G
L
A
R
U
T
A
N
F
O
Y
T
I
V
A
R
G
C
I
F
I
C
E
P
S
S
A
G
.
G
V
A
HEAT VALUE
0.58
0.60
0.62
0.64
AT ALTITUDE
Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press Orifice Mnfld Press
(Btu/cu ft)
No.
High/Low
No.
High/Low
No.
High/Low
No.
High/Low
TWO-STAGE FURNACE
(TABULATED DATA BASED ON 20,000 BTUH HIGH-HEAT / 13,000 BTUH LOW-HEAT PER BURNER,
DERATED 2%/1000 FT (305M) ABOVE SEA LEVEL)
ALTITUDE
RANGE
ft (m)
650
42
3.4 / 1.4
42
3.5 / 1.5
42
3.6 / 1.5
42
3.7 / 1.6
7001
675
43
3.8 / 1.6
42
3.2 / 1.4
42
3.3 / 1.4
42
3.4 / 1.5
(2134)
700
43
3.5 / 1.5
43
3.7 / 1.5
43
3.8 / 1.6
42
3.2 / 1.4
725
44
3.8 / 1.6
43
3.4 / 1.4
43
3.5 / 1.5
43
3.6 / 1.5
750
44
3.5 / 1.5
44
3.7 / 1.5
44
3.8 / 1.6
43
3.4 / 1.4
8000
775
44
3.3 / 1.4
44
3.4 / 1.4
44
3.5 / 1.5
44
3.7 / 1.5
(2438)
800
45
3.8 / 1.6
44
3.2 / 1.4
44
3.3 / 1.4
44
3.4 / 1.4
825
46
3.7 / 1.6
46
3.8 / 1.6
45
3.8 / 1.6
44
3.2 / 1.4
625
42
3.4 / 1.4
42
3.5 / 1.5
42
3.6 / 1.5
42
3.7 / 1.6
8001
650
43
3.8 / 1.6
42
3.2 / 1.4
42
3.3 / 1.4
42
3.4 / 1.4
(2439)
675
43
3.5 / 1.5
43
3.6 / 1.5
43
3.7 / 1.6
42
3.2 / 1.3
700
44
3.7 / 1.6
43
3.4 / 1.4
43
3.5 / 1.5
43
3.6 / 1.5
725
44
3.5 / 1.5
44
3.6 / 1.5
44
3.7 / 1.6
44
3.8 / 1.6
9000
750
44
3.3 / 1.4
44
3.4 / 1.4
44
3.5 / 1.5
44
3.6 / 1.5
(2743)
775
45
3.7 / 1.6
44
3.2 / 1.3
44
3.3 / 1.4
44
3.4 / 1.4
9001
600
42
3.3 / 1.4
42
3.4 / 1.5
42
3.6 / 1.5
42
3.7 / 1.6
(2744)
625
43
3.7 / 1.6
42
3.2 / 1.3
42
3.3 / 1.4
42
3.4 / 1.4
650
43
3.5 / 1.5
43
3.6 / 1.5
43
3.7 / 1.6
43
3.8 / 1.6
675
44
3.7 / 1.6
44
3.8 / 1.6
43
3.4 / 1.4
43
3.5 / 1.5
10000
700
44
3.4 / 1.4
44
3.5 / 1.5
44
3.7 / 1.5
44
3.8 / 1.6
(3048)
725
44
3.2 / 1.3
44
3.3 / 1.4
44
3.4 / 1.4
44
3.5 / 1.5
* Orifice numbers shown in BOLD are factory-installed.
to
to
to
U.
S
.A.
On
ly
U.
S
.A.
On
ly
U.
S
.A.
On
ly
A11252B
Adjust Temperature Rise
NOTE: Blower door must be installed when taking temperature
rise reading. Leaving blower door off will result in incorrect
temperature measurements, due to possible changes in duct
static pressure and airflow.
FURNACE DAMAGE HAZARD
Failure to follow this caution may result in:
S
Overheating the heat exchangers or condensing
flue gases in heat exchanger areas not designed
for condensate
S
Shortened furnace life
S
Component damage
Temperature rise must be within limits specified on furnace
rating plate. Recommended operation is at midpoint of rise
range or slightly above.
CAUTION
!
Place SW−1 (TT) in ON position. Jumper R to W/W1 and W2 to
check high−heat temperature rise. To check low−heat
temperature rise, remove jumper to W2. Determine air
temperature rise for both high and low−heat. Do not exceed
temperature rise ranges specified on unit rating plate for high
and low−heat.
This furnace must operate within the temperature rise ranges
specified on the furnace rating plate. Determine the air
temperature as follows:
1. Place duct thermometers in return and supply ducts as
close to furnace as possible. Be sure thermometers do
not “see” heat exchangers so that radiant heat does not
affect thermometer readings. This is particularly
important with straight run ducts.
2. When thermometer readings stabilize, subtract return−air
temperature from supply−air temperature to determine
temperature rise.
If the temperature rise is outside this range, check the
following:
1. Gas input for low and high heat operation.
2. Derate for altitude if applicable.
3. Return and supply ducts for excessive restrictions
causing static pressures greater than 0.50−in. w.c. (125
Pa)
4. Adjust temperature rise by adjusting blower speed.
S
Increase blower speed to reduce temperature rise.
S
Decrease blower speed to increase temperature rise.
ELECTRICAL OPERATION HAZARD
Failure to follow this warning could result in personal injury
or death.
Disconnect 115vac electrical power before changing speed
tap.
!