Set Temperature Rise; Set Thermostat Heat Anticipator - Bryant Series G 383KAV Installation, Start-Up, And Operating Instructions Manual

TABLE 6—MODEL 383KAV ORIFICE SIZE AND MANIFOLD PRESSURE FOR CORRECT INPUT
(TABULATED DATA BASED ON 22,000 BTUH PER BURNER, DERATED 4 PERCENT PER 1000 FT ABOVE SEA LEVEL)
AVG GAS
ALTITUDE
HEAT VALUE
RANGE
AT ALTITUDE
(FT)
(BTU/CU FT)
575
600
9001 625
650
to 675
700
10,000 725
750
775
e. Multiply gas rate (cu ft/hr) X heating value (Btu/cu ft)
using natural gas heating value from local gas
utility/supplier.
EXAMPLE: (0—2000 ft altitude)
Btu heating input = Btu/cu ft X cu ft/hr
Heating value of gas = 1050 Btu/cu ft
Time for 1 revolution of 2-cu ft dial = 70 sec
Gas rate = 103 cu ft/hr (from Table 8)
Btu heating input = 103 X 1050 = 108,150 Btuh
In this example, the orifice size and manifold pressure
adjustment is within ±2 percent of the furnace input rate.

2. Set temperature rise.

Furnace must operate within range of temperature rise
specified on the unit rating plate. Determine the air tem-
perature rise as follows.
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.
b. When thermometer readings stabilize, subtract return-air
temperature from supply-air temperature to determine
temperature rise.
c. Adjust air temperature rise by adjusting blower speed.
Increase blower speed to reduce temperature rise. De-
crease blower speed to increase temperature rise.
WARNING: Disconnect the electrical power before
changing the speed tap. A failure to follow this warning
can cause personal injury.
d. To change blower motor speed selections for heating
mode, remove blower motor lead from control board
HEAT terminal. (See Fig. 10.) Select desired blower
TABLE 7—ALTITUDE DERATE MULTIPLIER FOR U.S.A.
ALTITUDE PERCENT
(FT) OF DERATE
0—2000 0
2001—3000 8—12
3001—4000 12—16
4001—5000 16—20
5001—6000 20—24
6001—7000 24—28
7001—8000 28—32
8001—9000 32—36
9001—10,000 36—40
* Derate multiplier factor is based on midpoint altitude for altitude range.
0.58 0.60
Orifice Manifold Orifice
No. Pressure No.
43 2.7 43
43 2.5 43
43 2.3 43
43 2.1 43
48 3.7 43
48 3.4 48
49 3.8 48
49 3.5 49
49 3.3 49
DERATE MULTIPLIER
FACTOR FOR U.S.A*
1.00
0.90
0.86
0.82
0.78
0.74
0.70
0.66
0.62
—15—
SPECIFIC GRAVITY OF NATURAL GAS
0.62
Manifold Orifice Manifold
Pressure No. Pressure
2.8 43 2.9
2.6 43 2.7
2.4 43 2.4
2.2 43 2.3
2.0 43 2.1
3.6 48 3.7
3.3 48 3.4
3.6 49 3.8
3.4 49 3.5
TABLE 8—GAS RATE CU FT/HR
SIZE OF
SECONDS
TEST DIAL
FOR 1
1
REVOLUTION
cu ft
10 360
11 327
12 300
13 277
14 257
15 240
16 225
17 212
18 200
19 189
20 180
21 171
22 164
23 157
24 150
25 144
26 138
27 133
28 129
29 124
30 120
31 116
32 113
33 109
34 106
35 103
36 100
37 97
38 95
39 92
40 90
41 88
42 86
43 84
44 82
45 80
46 78
47 76
48 75
49 73
motor speed lead from 1 of the other terminals and
relocate it to HEAT terminal. See Table 9 for lead color
identification. Reconnect original lead on SPARE termi-
nal.
CAUTION: Recheck temperature rise. It must be within
limits specified on unit rating plate. Recommended op-
eration is at midpoint of rise or above.

3. Set thermostat heat anticipator.

The thermostat heat anticipator must be set to match the
amp draw of the electrical components in the R-W circuit.
Accurate amp draw readings can be obtained at thermostat
subbase terminals R and W. Fig. 14 illustrates an easy
Continued
0.64 0.66
Orifice Manifold Orifice
No. Pressure No.
43 3.0 43
43 2.7 43
43 2.5 43
43 2.3 43
43 2.2 43
43 2.0 43
48 3.5 48
48 3.3 48
49 3.6 49
SECONDS
TEST DIAL
FOR 1
2 5 1
REVOLUTION
cu ft cu ft cu ft
720 1800 50 72
655 1636 51 71
600 1500
52 69
555 1385 53 68
514 1286 54 67
480 1200 55 65
450 1125 56 64
424 1059 57 63
400 100 58 62
379 947 59 61
360 900 60 60
343 857 62 58
327 818 64 56
313 783 66 54
300 750 68 53
288 720 70 51
277 692 72 50
267 667 74 48
257 643 76 47
248 621 78 46
240 600 80 45
232 581 82 44
225 563 84 43
218 545 86 42
212 529 88 41
206 514 90 40
200 500 92 39
195 486 94 38
189
474 96 38
185 462 98 37
180 450 100 36
176 439 102 35
172 429 104 35
167 419 106 34
164 409 108 33
160 400
110 33
157 391
112 32
153 383
116 31
150 375
120 30
147 367
Manifold
Pressure
3.1
2.8
2.6
2.4
2.2
2.1
3.6
3.4
3.7
SIZE OF
2 5
cu ft cu ft
144 360
141 355
138 346
136 340
133 333
131 327
129 321
126 316
124 310
122 305
120 300
116 290
112 281
109 273
106 265
103 257
100 250
97 243
95 237
92 231
90 225
88 220
86 214
84 209
82 205
80 200
78 196
76 192
75 188
74 184
72 180
71 178
69 173
68 170
67 167
65 164
64 161
62 155
60 150