Set Temperature Rise - Carrier 58TUA Installation, Start-Up, And Operating Instructions Manual

Table 9—Gas Rate (Cu Ft/Hr)
SIZE OF TEST DIAL
SECONDS
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
18 200 400 100
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
adjust the manifold pressure (see item c) and replace the main
burner orifices as needed. Refer to NFGC 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.) Measured gas inputs should equal low- and high-fire
gas inputs on unit rating plate ± 2 percent.
(10.) Proceed to item c. to adjust manifold pressure.
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 manifold pressure
(1.) Move SW-2 to the ON position to lock out the
adaptive algorithm. (See Fig. 10 and 11.) Jumper R to
W/W1 and W2 to call for high-gas heat.
(2.) Remove gas control regulator adjustment seal caps.
(See Fig. 13.)
(3.) Turn high-fire adjusting screw (5/64-in. hex Allen
wrench) counterclockwise (out) to decrease input rate
SIZE OF TEST DIAL
SECONDS
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
110 33 65 164
112 32 64 161
116 31 62 155
120 30 60 150
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.
(4.) Remove R-to-W2 jumper to place furnace in low-fire
operation for low-fire adjustment.
(5.) 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.
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 (5.).
NOTE: If orifice hole appears damaged or it is suspected to have
been redrilled, check the orifice size with a numbered drill bit of
the correct size. Never use a redrilled orifice. A burr-free and
squarely aligned orifice hole is essential for proper flame charac-
teristics.
(6.) Remove jumper on R-W/W1 after low-fire adjust-
ments.
(7.) When correct input is obtained, replace regulator seal
caps. Main burner flame should be clear blue, almost
transparent. (See Fig. 14.)

2. Set temperature rise.

Place SW-2 in ON position. Jumper R to W/W1 and W2 to
check high-gas-heat temperature rise. To check low-gas-heat
temperature rise, remove jumper to W2. Determine air tem-
perature rise for both high and low fire. Do not exceed the
temperature rise ranges specified on the unit rating plate for
high and low fire.
a. Place duct thermometers in return and supply ducts as near
furnace as possible. Be sure thermometers do not see heat
exchangers so that radiant heat will not affect thermometer
readings. This is particularly important with straight run
ducts.
MANUAL
ON/OFF
INLET
PRESSURE
TAP
MANIFOLD
PRESSURE
TAP
Fig. 13—Redundant Automatic Gas Control Valve
b. When thermometer readings stabilize, subtract return-air
temperature from supply-air temperature to determine tem-
perature rise.
NOTE: If the temperature rise is outside this range, first check:
15
LOW-FIRE
ADJUSTMENT
ALLEN SCREW
(UNDER CAP)
HIGH-FIRE
ADJUSTMENT
ALLEN SCREW
(UNDER CAP)
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