Blower Off Delay (Heat Mode); Check Safety Controls; Check Primary Limit Control; Check Pressure Switch - Carrier 58MSA Installation, Start-Up, And Operating Instructions Manual

4-way multipoise fixed-capacity condensing for sizes 040—120 series 110
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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
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
3. Adjust temperature rise by adjusting blower speed. Increase
blower speed to reduce temperature rise. Decrease blower
speed to increase temperature rise.
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 termi-
nal. (See Fig. 27.) Select desired blower motor speed lead
from 1 of the other terminals and relocate it to HEAT terminal.
See Table 10 for lead color identification. Reconnect original
lead on SPARE terminal.
Follow this same procedure for proper selection of COOL
speed selection.
Table 10—Speed Selector
COLOR
Black
Yellow (When Present)
Blue
Red
White
SIZE OF TEST DIAL
SECONDS
FOR 1
1
2
REVOLUTION
cu ft
cu ft
50
72
144
51
71
141
52
69
138
53
68
136
54
67
133
55
65
131
56
64
129
57
63
126
58
62
124
59
61
122
60
60
120
62
58
116
64
56
112
66
54
109
68
53
106
70
51
103
72
50
100
74
48
97
76
47
95
78
46
92
80
45
90
82
44
88
84
43
86
86
42
84
88
41
82
90
40
80
92
39
78
94
38
76
96
38
75
98
37
74
100
36
72
102
35
71
104
35
69
106
34
68
108
33
67
110
33
65
112
32
64
116
31
62
120
30
60
FACTORY-
SPEED
SHIPPED
CONNECTION
High
Cool
Medium High
Spare
Medium Low
Heat
Low
Spare
Common
Com

BLOWER OFF DELAY (HEAT MODE)

The main blower off time delay period is factory-set at 135 sec and
is not field-adjustable.
5
cu ft
SET THERMOSTAT HEAT ANTICIPATOR
360
Thermostat heat anticipator must be set to match amp draw of
355
346
components in R-W circuit. Accurate amp draw measurements can
340
be obtained at thermostat subbase terminals R and W.
333
Fig. 42 illustrates an easy method of obtaining these measure-
327
321
ments. Amp reading should be taken after blower motor has
316
started. See thermostat manufacturer's instructions for adjusting
310
305
heat anticipator and for varying heating cycle length.
300
290
281
273
265
257
250
243
237
231
225
220
214
209
205
200
196
192
188
184
180
178
173
170
167
164
161
5.0 AMPS ON AMMETER
EXAMPLE:
10 TURNS AROUND JAWS
155
150
Fig. 42—Amp Draw Check with Ammeter

CHECK SAFETY CONTROLS

Step 1—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.
Step 2—Check Pressure Switch
This control proves operation of draft inducer. Check switch
operation as follows:
1. Turn off 115-v power to furnace.
2. Remove main furnace door and disconnect inducer motor lead
wires from wire harness.
3. Turn on 115-v power to furnace.
4. Set thermostat to "call for heat" and wait 1 minute. When
pressure switch is functioning properly, hot surface ignitor
should NOT glow, and control center diagnostic light flashes
a 31 fault. If hot surface ignitor glows when inducer motor is
disconnected, shut furnace down immediately. Determine
reason pressure switch did not function properly and correct
condition.
38
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
A80201

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