Carrier F97CMN - Page 56

F97CMN and G97CMN: Installation, Start-up, Operating and Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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3. Jumper R to W/W1 and W2. Run furnace for 3 minutes in
maximum heat operation.
4. Measure time (in sec) for gas meter to complete one revolution and
note reading. The 2 or 5 cubic feet dial provides a more accurate
measurement of gas flow.
5. Refer to Table 17 for cubic ft. of gas per hr. Multiply gas rate cu
ft./hr by heating value (Btuh/cu ft.) to obtain input rate.
6. If clocked rate does not match required input from Step 5, increase
manifold pressure to increase input or decrease manifold pressure
to decrease input. Repeat steps 3 through 5 until correct maximum
heat input is achieved. See Fig. 57.
NOTE: Setup switches SW1-2 must be ON and SW4-2 must be OFF.
This keeps furnace locked in minimum heat operation when R to W/W1
is energized. Repeat items 3 through 6 for minimum heat operation until
minimum heat input is achieved.
7. Remove jumpers across thermostat connections to terminate the
call for heat. Wait until the blower off delay is completed then reset
115-v power to furnace.
8. Restore furnace to normal operating condition.
A11461
Fig. 63 – Burner Flame
9. Remove jumpers across thermostat connections to termi-nate the
call for heat. Wait until the blower off delay is completed.
10. Disconnect 115 VAC power to furnace.
11. Turn gas valve ON/OFF switch to OFF.
12. Remove water column manometer or similar device from manifold
pressure tap.
13. Tighten set screw on manifold tower pressure tap with 3/32-in hex
wrench, or if 1/8-in. NPT plug was removed, apply pipe dope
sparingly to end of plug and reinstall in the gas valve.
14. Turn gas valve ON/OFF switch to ON.
15. Move setup SW1-2 on furnace control to position required for
attached thermostat (OFF for single-stage thermostats, ON for
two-stage thermostats).
16. Check for gas leaks and verify furnace operation.
Table 17 – Gas Rate (CU ft./hr)
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.
WARNING
!
FIRE HAZARD
Failure to follow this warning could result in personal injury, death,
and/or property damage.
Manifold pressure tap set screw must be tightened or ⅛-in. NPT pipe
plug must be installed to prevent gas leaks.
Burner Flame
Burner
Manifold
SECONDS
FOR 1 REV
SIZE OF TEST DIAL
SECONDS
FOR 1 REV
SIZE OF TEST
DIAL
1 Cu
Ft.
2 Cu
Ft.
5 Cu
Ft.
1 Cu
Ft.
2 Cu
Ft.
5 Cu
Ft.
10
360 720 1800 50 72 144 360
11
327 655 1636 51 71 141 355
12
300 600 1500 52 69 138 346
13
277 555 1385 53 68 136 340
14
257 514 1286 54 67 133 333
15
240 480 1200 55 65 131 327
16
225 450 1125 56 64 129 321
17
212 424 1059 57 63 126 316
18
200 400 1000 58 62 124 310
19
189 379 947 59 61 122 305
20
180 360 900 60 60 120 300
21
171 343 857 62 58 116 290
22
164 327 818 64 56 112 281
23
157 313 783 66 54 109 273
24
150 300 750 68 53 106 265
25
144 288 720 70 51 103 257
26
138 277 692 72 50 100 250
27
133 267 667 74 48 97 243
28
129 257 643 76 47 95 237
29
124 248 621 78 46 92 231
30
120 240 600 80 45 90 225
31
116 232 581 82 44 88 220
32
113 225 563 84 43 86 214
33
109 218 545 86 42 84 209
34
106 212 529 88 41 82 205
35
103 206 514 90 40 80 200
36
100 200 500 92 39 78 196
37
97 195 486 94 38 76 192
38
95 189 474 96 38 75 188
39
92 185 462 98 37 74 184
40
90 180 450 100 36 72 180
41
88 176 439 102 35 71 178
42
86 172 429 104 35 69 173
43
84 167 419 106 34 68 170
44
82 164 409 108 33 67 167
45
80 160 400 110 33 65 164
46
78 157 391 112 32 64 161
47
76 153 383 116 31 62 155
48
75 150 375 120 30 60 150
49
73 147 367
CAUTION
!
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.