Check Safety Controls - International comfort products F9MXT0401410A Service And Technical Support Manual

SERVICE AND TECHNICAL SUPPORT MANUAL
Table 6 AIR DELIVERY - CFM (with filter
UNIT RETURN-AIR
SPEED
SIZE CONNECTION
TAPS
0401410 SIDE/BOTTOM
Orange
0401712 SIDE/BOTTOM
Orange
0601412 SIDE/BOTTOM Orange
0601714 SIDE/BOTTOM
Orange
0801716 SIDE/BOTTOM
Orange
BOTTOM or
0802120
4, 5
TWO-SIDES
Orange
BOTTOM or
1002120
4, 5
TWO-SIDES
Orange
BOTTOM or
1202422
4, 5
TWO-SIDES
Orange
NOTE:
1. A filter is required for each return−air inlet. Airflow performance includes a 3/4 in. (19 mm) washable filter media such as contained in factory−authorized accessory
filter rack. See accessory list. To determine airflow performance without this filter, assume an additional 0.1 in. W.C. available external static pressure.
2. ADJUST THE BLOWER SPEED TAPS AS NECESSARY FOR THE PROPER AIR TEMPERATURE RISE FOR EACH INSTALLATION.
3. Shaded areas indicate that this airflow range is BELOW THE RANGE ALLOWED FOR HIGH−STAGE HEATING OPERATION. THESE AIRFLOW RANGES MAY
ONLY BE USED FOR LOW−STAGE HEAT OR COOLING.
4. 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.
5. 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.
6. The "−" entry indicates an unstable operating condition.

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.
12
EXTERNAL STATIC PRESSURE (in. w.c.)
2
0.1 0.2
Gray 1120 1080
Yellow 880 845
Blue 695 665
640 595
Red 570 525
Gray 1255 1220
Yellow 940 905
Blue 705 670
580 535
Red 555 485
Gray 1265 1225
Yellow 1115 1085
1000 970
Blue 945 915
Red 770 740
Gray 1720 1670
Yellow 1325 1285
Blue 1010 970
1160 1115
Red 785 715
Gray 1810 1770
Yellow 1535 1500
Blue 1380 1340
1180 1130
Red 1100 1045
Gray 2290 2225
Yellow 1810 1760
Blue 1385 1340
1560 1520
Red 1055 985
Gray 2340 2295
Yellow 1950 1900
Blue 1750 1700
1570 1520
Red 1350 1280
Gray 2275 2230
Yellow 1875 1820
Blue 2170 2125
3
1475 1420
3
Red 1625 1565
Specifications subject to change without notice.
1
)
0.3 0.4 0.5
1030 980 925
810 780 740
620 575 535
540 495 460
475 425 385
1175 1130 1085 1040
870 840 805
630 575 540
480 425 380
425 375 330
1185 1140 1090 1030
1060 1030 1000
940 910 880
885 855 820
700 660 620
1620 1565 1505 1440
1255 1220 1185 1145
925 875 835
1080 1045 1000
655 595 530
1720 1665 1610 1540
1475 1435 1405 1370
1305 1270 1240 1200
1095 1060 1015
1010 970 920
2155 2090 2015 1930
1725 1685 1640 1600
1285 1240 1200 1140
1475 1430 1385 1335
910 860 795
2250 2195 2110 2030
1855 1800 1755 1705
1650 1605 1555 1500
1460 1410 1350 1300
1225 1155 1105 1045
2185 2130 2055 1950
1770 1720 1660 1600
2075 2025 1975 1900
1350 1280 1215 1165
1505 1445 1385 1325
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 115−V power to furnace.
b. Disconnect inducer motor lead wires from wire
harness.
c. Turn on 115−V power to furnace.
d. Set thermostat to "call for heat" and wait 1 minute.
When pressure switch is functioning properly, hot
surface igniter should NOT glow and control
diagnostic light flashes a status code 3. If hot surface
Gas Furnace: (F/G)9MXT
0.6 0.7 0.8 0.9
875 820 760 690
710 680 640 615
495 455 420 370
420 370 310 260
330 255 220
990 940 880
770 735 695 665
500 455 410 380
335 290 235
6
280 215 -
975 920 850
970 930 880 810
845 815 770 735
785 745 705 675
575 540 500 455
1375 1295 1220
1115 1075 1040
785 745 690 660
960 920 875 840
490 435 385 340
1475 1400 1315
1340 1310 1245
1165 1130 1090
975 935 895 850
885 845 790 745
1845 1750 1640
1555 1520 1480
1090 1050 995
1295 1240 1200
750 680 615 565
1935 1835 1725
1655 1605 1560
1455 1395 1350
1240 1195 1140
1000 950 895
1825 1710 1610
1550 1505 1450
1790 1695 1590
1105 1050 995
1275 1225 1170
440 04 4321 08
1.0
630
570
280
230
6 6
- -
825
630
325
6 6
- -
6 6
- -
760
715
695
635
415
1135
1000
620
785
285
1235
1160
1050
800
690
1515
1415
950
1150
495
1605
1485
1300
1095
830
1500
1390
1470
930
1130