Carrier 58SX040-IBC - Manual (Page 6)

7. Open K-W circuit.
8. Disconnect slope gage.
9. Remove plastic tees and reconnect factory pressure
tubes to gas valve and pressure switch.
10. Turn on gas supply to furnace.
Ignition System Check— When all connections have been
checked, light the furnace using procedure outlined on light­
ing instruction attached to furnace. When lighting the fur­
nace for the first time, however, perform the following addi­
tional steps:
1. If gas supply was not piurged before connecting fur­
nace, line will be full of air. Loosen ground joint union
and allow supply line to purge until gas odor is
detected. Never purge gas lines into a combustion
chamber. Immediately upon detection of gas odor,
retighten union. After 5 minutes, light fmrnace in
accordance with instructions on furnace rating plate.
2. Main burners should light 25 to 75 seconds after pilot.
If main burners do not light within prescribed time
period, check pilot ñame.
3. The pilot ñame should be soft blue in color and it must
provide good impingement on the pilot switching ele­
ment. The ñame should extend above the burner carry­
over port to provide a proper burner ignition. When the
pilot flame requires adjustment:
a. Locate adjustment screw marked “PILOT ADJ” on
top of gas valve.
b. Remove cap and turn adjustment screw clockwise
to decrease pilot gas flow. Turn screw counterclock­
wise to increase pilot gas flow.
c. When proper adjustment is obtained, replace screw
cap.
Gas Input
NOTE: Be sure reference pressmre tube, combustion-air and
vent pipes, and burner enclosure front are in place when
clocking the gas meter.
1. Determine gas input.
a. Turn off all other gas appliances and pilots.
b. Measure time (in seconds) for gas meter test dial to
complete one revolution.
c. Refer to Table 4 for cu ft of gas per hour.
d. Multiply cu ft/hr by heating value of gas (Btu/cu ft)
obtained from local gas utility.
EXAMPLE:
Btu heating input = Btu/cu ft times cu ft/hr
Heating value of gas = 1070 Btu/cu ft
Time for one revolution of 2-cu-ft dial = 72 sec
Gas rate = 100 cu ft/hr (from Table 4)
Btu heating input = 1070x100 = 107,000 Btuh
e. Measm-ed gas input must not exceed gas input on
unit rating plate.
2. To adjust input rate:
a. Remove burner enclosure front and cap that con­
ceals adjustment screw for gas valve regulator.
b. Turn adjusting screw either counterclockwise (out)
to decrease input rate or clockwise to increase rate.
When adjusting input rate, do NOT change mani­
fold pressure more than 3.2 minimum to 3.8 maxi­
mum in. wc. Make any major adjustments by
changing main burner orifices.
NOTE: Manifold pressure must always be measured with
burner enclosure front removed. The gas meter must always
be clocked with burner enclosure front installed.
DIGITAL MANOMETER
A84220
Fig. 6—Tuning Valve Adjustment
c. Replace burner enclosure front and measure
adjusted gas input rate using method outlines in
step 1.
d. Replace cap that conceals gas valve regulator
adjustment screw.
A CAUTION
Be sure burner enclosure front is in place after adjust­
ments have been made.
3. Look through sight glass in burner enclosure and check
burner and pilot flame. The main biurner flame should
be clear blue, almost transparent. The pilot flame
should be well defined. See Fig. 7.
Table 4—Gas Rate in Cu Ft/Hr
SECONDS SIZE OF SECONDS SIZE OF
FOR ONE TEST DIAL FOR ONE TEST DIAL
REVOLU- 1 2 5 REVOLU- 1 2 5
TION cu ft cu ft cu ft TION cu ft cu ft 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
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