Bryant 349HAV Series Installation, Start-Up, And Operating Instructions Manual page 16

TABLE 6—GAS RATE CU FT/HR
SECONDS SIZE OF TEST DIAL
FOR 1 1 2 5
REVOLUTION cu ft cu ft cu ft
10 360 720 1800
11 327 655 1636
12 300 600 1500
13 277 555 1385
14
257 514 1286
15 240 480 1200
16 225 450 1125
17 212 424 1059
18 200 400 10 0
19 189 379 947
20 180 360 900
21 171 343 857
22 164 327 818
23 157 313 783
24 150 300 750
25 144 288 720
26 138 277 692
27 133 267 667
28 129 257 643
29 124 248 621
30 120 240 600
31 116 232 581
32 113 225 563
33 109 218 545
34 106 212 529
35 103 206 514
36 100 200 500
37 97 195 486
38 95 189 474
39 92 185 462
40 90 180 450
41 88 176 439
42 86 172 429
43 84 167 419
44 82 164 409
45 80 160 400
46 78 157 391
47 76 153 383
48 75 150 375
49 73 147 367
TABLE 7—CANADIAN ORIFICE SIZE
SEA LEVEL
GAS
0-2000 FT
Natural 42
Propane 54
3. Adjust gas input.
NOTE: The gas valve has been nominally set at 3.5-in. wc for
natural gas.
a. Remove cap that conceals adjustment screw for gas
valve regulator. (See Fig. 15.)
b. Turn adjusting screw either counterclockwise (out) to
decrease input rate or clockwise (in) to increase rate.
When adjusting input rate, DO NOT set manifold
pressure less than 3.2-or more than 3.8-in. wc for natural
gas. Make any major adjustments by changing main
burner orifices.
WARNING: DO NOT redrill orifices. Improper drilling
(burrs, out-of-round holes, etc.) can cause excessive
burner noise and misdirection of burner flames. This can
result in flame impingement of the burners and heat
exchangers causing failures.
NOTE: If orifice hole appears damaged or it is suspected to have
been redrilled, check the orifice hole with the correct size
numbered drill bit. Never redrill an orifice. A burr-free and
squarely aligned orifice hole is essential for proper flame charac-
teristics.
c. Measure adjusted gas input rate using method outlined in
item 2.
SECONDS SIZE OF TEST DIAL
FOR 1 1 2 5
REVOLUTION cu ft cu ft cu ft
50 72 144 360
51 71 141 355
52 69 138 346
53 68 136 340
54 67 133 333
55 65 131 327
56 64 129 321
57 63 126 316
58 62 124 310
59 61 122 305
60 60 120 300
62 58 116 290
64 56 112 281
66 54 109 273
68 53 106 265
70 51 103 257
72 50 100
250
74 48 97 243
76 47 95 237
78 46 92 231
80 45 90 225
82 44 88 220
84 43 86 214
86 42 84 209
88 41 82 205
90 40 80 200
92 39 78 196
94 38 76 192
96 38 75 188
98 37 74 184
100 36 72 180
102 35 71 178
104 35 69 173
106 34 68 170
108 33 67 167
33 65 164
110
32 64 161
112
31 62 155
116
30 60 150
120
HIGH ALTITUDE
2000-4500 FT
43
55
IGNITOR
CONNECTOR
PILOT
ADJUSTMENT
(UNDER CAP
SCREW)
PILOT
OUTLET
MANIFOLD
PRESSURE
TAP
→ Fig. 15—Honeywell SmartValve
d. Replace cap that conceals gas valve regulator adjustment
screw.
CAUTION: Be sure burner enclosure front is in place
after adjustments have been made.
e. Look through openings in burner enclosure and check
burner flame. The main burner flame should be clear
blue, almost transparent. (See Fig. 16.)
PILOT FLAME
Fig. 16—Pilot and Burner Flames
4. Change burner orifice (if necessary).
The furnace is supplied with standard orifices for the gas
shown on rating plate. If orifices need to be changed to
achieve proper input rate, proceed as follows:
a. Remove manifold pipe cover and burner removal
cover/air inlet plate.
b. Remove manifold retention plate.
c. Pull manifold/burner assembly out past support pins and
remove assembly.
—16—
IGNITION SYSTEM
CONTROL SWITCH
IGNITION
MODULE
INLET
PRESSURE
TAP
GAS
PRESSURE
REGULATOR
ADJUSTMENT
(UNDER CAP
SCREW)
BURNER FLAME
MANIFOLD
A98304
BURNER
A84076