A warning, A caution – Carrier 58PAV User Manual

Page 15

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Table 16—Gas Rate Cu Ft/Hr

Seconds

SIZE OF TEST DIAL

Seconds

SIZE OF TEST DIAL

for one

1

2

5

for one

1

2

5

Revolution

cu ft CU ft CU ft

Revolution

cu ft cu ft cu ft

10

360

720

1800

50

72

144

360

11

327

655

1636

51

71

141

355

12

300

600

1500

52

69

138

346

13

277

555

1385

53

68

136

340

14

257

514

1286

54

67

133

333

15

240

480

1200

55

65

131

327

16

225

450

1125

56

64

129

321

17

212

424

1059

57

63

126

316

18

200

400

1000

58

62

124

310

19

189

379

947

59

61

122

305

20

180

360

900

60

60

120

300

21

171

343

857

62

58

116

290

22

164

327

818

64

56

112

281

23

157

313

783

66

54

109

273

24

150

300

750

68

53

106

265

25

144

288

720

70

51

103

257

26

138

277

692

72

50

100

250

27

133

267

667

74

48

97

243

28

129

257

643

76

47

95

237

29

124

248

621

78

46

92

231

30

120

240

600

80

45

90

225

31

116

232

581

82

44

88

220

32

113

225

563

84

43

86

214

33

109

218

545

86

42

84

209

34

106

212

529

88

41

82

205

35

103

206

514

90

40

80

200

36

100

200

500

92

39

78

196

37

97

195

486

94

38

76

192

38

95

189

474

96

38

75

188

39

92

185

462

98

37

74

184

40

90

180

450

100

36

72

180

41

88

176

439

102

35

71

178

42

86

172

429

104

35

69

173

43

84

167

419

106

34

68

170

44

82

164

409

108

33

67

167

45

80

160

400

110

33

65

164

46

78

157

391

112

32

64

161

47

76

153

383

116

31

62

155

48

75

150

375

120

30

60

150

49

73

147

367

d. Approved input ratings.

The U.S.A. ratings are approved for altitudes up to
2000 ft for natural and propane gases. Refer to
National Fuel Gas Code Appendix F, Table F-4 for
proper orifice sizing at high altitudes,

e. Canadian installations only.

The Canadian ratings are approved for altitudes up
to 2000 ft for natural and propane gases. High alti­
tude ratings are from 2000 ft to 4500 ft above sea
level. See Table 17 for nominal burner orifice size.
High altitude rating includes a 10% derate as
required by Canadian standards.

Table 17—Canadian Orifice Size

Sea Level

High Altitude

Gas

0—2000 ft

20Ô0—4500 ft

Natural

43

44

Propane

54

55

2. Set temperature rise.

Do not exceed the temperature rise range specified on
the unit rating plate. Determine the air temperature

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 partic­
ularly 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. Decrease blower speed to increase temperature
rise.

A WARNING

Disconnect the electrical power before changing the
speed tap. A failure to follow this warning can cause
personal injury.

d. To change motor speed taps, remove the motor tap

lead (see Table 18) and relocate it on the desired ter­
minal on the plug-in terminal block/speed selector
located on the blower housing.

A CAUTION

Recheck the temperature rise. It must be within the
Hmits specified on the unit rating plate. Recommended
operation at mid-point of rise or above.

Table 18—Speed Selector

Speed

Tap No.*

Common

C

Hi

1

Med-Hi

2

Med-Low

3

Low

4

*White wire from control box to common; black wire from control box to

cooling speed selection; red wire from control box to heating and con­
stant fan speed selection.

3. Set thermostat heat anticipator.

The thermostat heat anticipation 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 & W. Fig. 16 illus­
trates an easy method of obtaining the actual amp
draw. The amp reading should be taken after the
blower motor has started. See the thermostat manufac­

turer’s instructions for adjusting the heat anticipator

and for varying the heating cycle length.

NOTE:

When using an electronic thermostat, set the cycle

rate for three cycles per hour.

E. Check Safety Controls

The flame sensor, gas valve, and pressure switch were all
checked in the Startup Section as part of normal operation.

Fig. 16—Amp Draw Check With Ammeter

15

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