Adjust Blower Off Delay (Heat Mode); Set Thermostat Heat Anticipator; Check Safety Controls; Check Primary Limit Control - Bryant D Series Installation, Start-Up, And Operating Instructions Manual

TABLE 11—GAS RATE (CU FT/HR)
SECONDS 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 1000
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
2. When thermometer readings stabilize, subtract return-air
temperature from supply-air temperature to determine air
temperature rise.
3. Adjust temperature rise by adjusting blower speed. Increase
blower speed to reduce temperature rise. Decrease blower
speed to increase temperature rise.
WARNING: Disconnect 115-v electrical power before
changing speed tap. Failure to follow this warning could
result in personal injury.
4. To change blower motor speed selections for heating mode,
remove blower motor lead from control center HEAT
terminal. (See Fig. 25.) Select desired blower motor speed
lead from 1 of the other terminals and relocate it to HEAT
terminal. See Table 12 for lead color identification. Recon-
nect original lead on SPARE terminal.
Follow this same procedure for proper selection of COOL
speed selection.
TABLE 12—SPEED SELECTOR
COLOR
Black
Yellow (When Present)
Blue
Red
White
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
110 33 65 164
112 32 64 161
116 31 62 155
120 30 60 150
FACTORY-
SPEED SHIPPED
CONNECTION
High Cool
Medium High Spare
Medium Low Heat
Low Fan
Common L2
C. Adjust Blower Off Delay (Heat Mode)
If desired, the main blower off time delay period may be
lengthened or shortened when operating in the heating mode to
provide greater comfort. Position shunt jumpers as shown in Table
13 and Fig. 25 for location of switches on control center.
TABLE 13—BLOWER OFF DELAY JUMPER
DESIRED HEATING
MODE BLOWER OFF
DELAY (SEC)
90
135
180
225
D. Set Thermostat Heat Anticipator
Thermostat heat anticipator must be set to match amp draw of
components in R-W circuit. Accurate amp draw measurements can
be obtained at thermostat subbase terminals R and W.
Fig. 51 illustrates an easy method of obtaining these measure-
ments. Amp reading should be taken after blower motor has
started. See thermostat manufacturer's instructions for adjusting
heat anticipator and for varying heating cycle length.
5.0 AMPS ON AMMETER
EXAMPLE:
10 TURNS AROUND JAWS
Fig. 51—Amp Draw Check with Ammeter

CHECK SAFETY CONTROLS

I. CHECK PRIMARY LIMIT CONTROL
This control shuts off combustion control system and energizes
air-circulating blower motor if furnace overheats. Recommended
method of checking this limit control is to gradually block off
return air after furnace has been operating for a period of at least
5 minutes. As soon as limit control has shut off burners, return-air
opening should be unblocked to permit normal air circulation. By
using this method to check limit control, it can be established that
limit is functioning properly and operates if there is a restricted
return-air supply or motor failure. If limit control does not function
during this test, cause must be determined and corrected.
II. CHECK PRESSURE SWITCH
This control proves operation of draft inducer. Check switch
operation as follows:
1. Turn off 115-v power to furnace.
—44—
POSITION
JUMPER POSITION
1-2
2-3
3-4
4-5
THERMOSTAT SUBBASE
TERMINALS WITH
THERMOSTAT REMOVED
HOOK-AROUND
VOLT/AMMETER
R Y W G
10 TURNS
FROM UNIT 24-VOLT
TERMINAL BLOCK
= 0.5 AMPS FOR THERMOSTAT SETTING
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