Carrier 100 Series - Input Rate

EXAMPLE:
Heat value 1040
Btu/cu ft specific gravity 0.62
Therefore; Orifice No. 45* with manifold pressure 3.7-in.
wc on high fire and 1.6-in. wc on low fire. * The furnace is
shipped with No. 44 orifices. Therefore, in this example all
main burner orifices must be changed and manifold pres¬
sure must be adjusted.
(7.) Proceed to item c. to adjust manifold pressure.
Table 12-^Gas Rate Cu Ft/Hr
SECONDS
FOR 1
REVOLUTION
SIZE OF TEST DIAL
SECONDS
FOR 1
REVOLUTION
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
400 100
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
46
47
48
49
80
78
76
75
73
160
157
153
150
147
400
391
383
375
367
110
112
116
120
33
32
31
30
65
64
62
60
164
161
155
150
b. Check gas input rate by clocking gas meter for low and
high fire.
(1.) Obtain average yearly heat value for local gas supply.
NOTE: Be sure heating value used for calculations is correct for
your altitude. Consult local gas utility for altitude adjustments of
gas heating value.
(2.) Check and verify orifice size in furnace. NEVER
ASSUME THE ORIFICE SIZE. ALWAYS CHECK
AND VERIFY.
(3.) Turn off all other gas appliances and pilots.
(4.) Turn SW2 to ON. Close R to WAVl and jumper R to
W2 to start furnace in high fire and let run for 3
minutes.
(5.) Measure time (in sec) for gas meter to complete 1
revolution.
(6.) Refer to Table 12 for cubic ft of gas per hour.
(7.) Multiply gas rate (cubic ft/hr) X heating value (Btu/
cubic ft).
EXAMPLE:
Btu heating input=Btu/cu ft X cu ft/hr
Heating value of gas 1070 Btu/cu ft
Time for 1 revolution of 2-cu/ft dial 72 sec
Gas rate= 100 X 1070=107,000 Btuh
(8.) Measured gas input should equal low and high fire gas
inputs on unit rating plate, ± 2 percent.
NOTE: High altitude— I n the United States, gas input on rating
plate is for altitudes up to 2000 ft. Ratings for altitudes over 2000
ft MUST be reduced 4 percent for each 1000 ft above sea level. To
obtain the altitude-adjusted rating, adjust the manifold pressure,
item c., and replace the main burner orifices as needed. Refer to
National Fuel Gas Code Appendix F, Table F-4 for proper orifice
sizing at high altitudes.
NOTE: Canadian installations only—The Canadian ratings are
approved for altitudes up to 2000 ft for natural and propane gases.
High-altitude ratings are from 2000 ft to 4500 ft above sea level.
High-altitude rating includes a 10 percent derate as required by
Canadian standards.
(9.) Remove jumper R to W2 and repeat items 5 through 8
for low fire.
(10.) Proceed to item c. to adjust manifold pressure.
A CAUTION
DO NOT redrill burner orifices. Improper drilling (burrs, out
of round, etc.) can cause excessive burner operating noise and
misdirection of burner flames. This could result in flame
impingement on burners and heat exchanger surfaces, leading
to potential failures.
c. Adjust gas input.
(1.) Move SW2 to the ON position (See Fig. 13.) to lock
furnace in low-fire. Jumper R to W/Wl to call for low
gas heat.
(2.) Remove gas control regulator adjustment seal caps.
(See Fig. 13.)
(3.) Turn low-fire adjusting screw (5/64-in. hex Allen
wrench) counterclockwise (out) to decrease input rate
or clockwise (in) to increase rate. When adjusting
input rate, DO NOT set manifold pressure less than
1.3-in. wc or more than 1.7-in. wc for natural gas. If
manifold pressure is outside this range, change main
burner orifices.
(4.) Turn SW2 to the OFF position after low-fire adjust¬
ment.
(5.) Jumper R-to-W/Wl terminal connections on control to
keep furnace in high-fire adjustment,
(6.) Turn high-fire adjusting screw (5/64-in. hex Allen
wrench) 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-in wc or more than 3.8-in. wc for natural gas. If
manifold pressure is outside this range, change main
burner orifices.
NOTE: If orifices are changed, both high fire and low fire input
rates must be readjusted, with manifold pressures within ranges
specified in items 3 and 6.
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