Set Temperature Rise; Set Thermostat Heat Anticipator - Carrier 58MVP Installation, Start-Up, And Operating Instructions Manual

m. Move setup switch SW1-2 to OFF position and jumper R
and W/W1 and W2 thermostat connections. (See Fig. 32.)
This keeps furnace locked in high-heat operation. Repeat
items i through l for high-heat operation.
EXAMPLE: (High-heat operation at 0—2000 ft altitude)
Furnace input from rating plate is 100,000 Btuh
Btu heating input = Btu/cu ft X cu ft/hr
Heating value of gas = 975 Btu/cu ft
Time for 1 revolution of 2-cu ft dial = 70 sec
Gas rate = 103 cu ft/hr (from Table 13)
Btu heating input = 103 X 975 = 100,425 Btuh In this
example, the orifice size and manifold pressure adjustment
is within ±2 percent of the furnace input rate.
NOTE: Measured gas inputs (high heat and low heat) must be
within ±2 percent of that stated on furnace rating plate when
installed at sea level or derated per that stated above when installed
at higher altitudes.
n. Remove jumper across R, W/W1, and W2 thermostat
connections to terminate call for heat.
Table 13—Gas Rate Cu Ft/Hr
SIZE OF TEST DIAL
SECONDS
FOR 1
1 2
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
SIZE OF TEST DIAL
SECONDS
FOR 1
5 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

SET TEMPERATURE RISE

Temperature rise must be within limits specified on unit
rating plate. Operation is within a few degrees of midpoint of
rise range when setup switch SW1-4 is OFF. Failure to follow
this caution may result in overheating the heat exchangers or
condensing flue gas in heat exchanger areas not designed for
condensate.
Furnace must operate within ranges of temperature rise specified
on the furnace rating plate. Determine air temperature rise as
follows:
1. Place thermometers in return and supply ducts as near furnace
as possible. Be sure thermometers do not see heat exchanger
so that radiant heat does not affect readings. This practice is
particularly important with straight-run ducts.
2. When thermometer readings stabilize, subtract return-air tem-
perature from supply-air temperature to determine air tem-
perature rise.
NOTE: Temperature rise can be determined for low-heat opera-
tion by placing setup switch SW1-2 on furnace control in ON
position. For high-heat operation, place setup switch SW1-2 in
OFF position and jumper R-W2 on furnace control. DO NOT
forget to return setup switch to OFF position and remove R-W2
jumper upon completion of testing. (See Fig. 32 for switch and
terminal location.)
3. This furnace is capable of automatically providing proper
airflow to maintain the temperature rise within the range
specified on furnace rating plate. If temperature rise is outside
this range, proceed as follows:
a. Check gas input for low- and high-heat operation.
5
cu ft
b. Check derate for altitude if applicable.
360
c. Check all return and supply ducts for excessive restrictions
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346
causing static pressure greater than 0.5-in. wc.
340
d. Ensure Low Heat Rise Adjust switch SW1-3 on furnace
333
control is in ON position when a bypass humidifier is used.
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321
(See Fig. 32 for switch location.)
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310 e. Check Troubleshooting Guide for Variable-Speed 2-Stage
305
Electronic Condensing Furnaces Series 170 and later.
300

SET THERMOSTAT HEAT ANTICIPATOR

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281
When using a non-electronic thermostat, the thermostat heat
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anticipator must be set to match the amp draw of components in
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257 the R-W/W1 circuit. Accurate amp draw measurements can be
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obtained only at the thermostat subbase terminals R and W.
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237
The thermostat and anticipator should NOT be in the circuit while
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measuring current. If thermostat has no subbase, the thermostat
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must be disconnected from R and W/W1 wires during current
220
measurement.
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209
Fig. 65 illustrates an easy method of obtaining thermostat amp
205
draw measurements. The amp reading should be taken after blower
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196
motor has started and furnace is operating in low-heat.
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1. To operate furnace in low-heat, turn setup switch SW1-2 to
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184
ON position (See Fig. 32) and connect ammeter leads across
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thermostat subbase R-W.
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2. See thermostat manufacturer's instructions for adjusting the
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heat anticipator and for varying heating cycle length.
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NOTE: When using an electronic thermostat, set cycle rate for 3
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cycles per hr.
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155
3. Return setup switch SW1-2 to OFF position and replace
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thermostat on subbase.
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