91
Main Burners (48PG Only) —
For all applications,
main burners are factory set and should require no adjustment.
MAIN BURNER REMOVAL
1. Shut off (field-supplied) manual main gas valve.
2. Shut off power to unit.
3. Remove gas section access panel.
4. Disconnect gas piping from gas valve inlet.
5. Remove wires from gas valve.
6. Remove wires from rollout switch.
7. Remove sensor wire and ignitor cable from IGC board.
8. Remove 2 screws securing manifold bracket to basepan.
9. Remove 2 screws that hold the burner assembly to vesti-
bule plate.
10. Lift burner/manifold assembly out of unit.
CLEANING AND ADJUSTMENT
1. Remove burner rack from unit as described in Main
Burner Removal section above.
2. Inspect burners, and if dirty, remove burners from rack.
3. Using a soft brush, clean burners and crossover port as
required.
4. Adjust spark gap. See Fig. 47.
5. Reinstall burners on rack.
6. Reinstall burner rack as described above.
Table 58 — Altitude Compensation* — 48PG20-28
NATURAL GAS
*As the height above sea level increases, there is less oxygen per
cubic foot of air. Therefore, heat input rate should be reduced at
higher altitudes. Includes a 4% input reduction per each 1000 ft.
†Orifices available through your Carrier dealer.
PROPANE GAS
*As the height above sea level increases, there is less oxygen per
cubic foot of air. Therefore, heat input rate should be reduced at
higher altitudes. Includes a 4% input reduction per each 1000 ft.
†Orifices available through your Carrier dealer.
ELEVATION
(ft)
NATURAL GAS ORIFICE SIZE†
Low Heat
(D,L)
Medium Heat
(E,M)
High Heat
(F,N)
0-1,999
29
30
29
2,000
29
30
29
3,000
30
31
30
4,000
30
31
30
5,000
30
31
30
6,000
30
31
30
7,000
31
32
31
8,000
31
32
31
9,000
31
32
31
10,000
32
33
32
ELEVATION
(ft)
PROPANE GAS ORIFICE SIZE†
Low Heat
(D,L)
Medium Heat
(E,M)
High Heat
(F,N)
0-1,999
35
38
35
2,000
36
39
36
3,000
36
39
36
4,000
37
40
37
5,000
37
40
37
6,000
38
41
38
7,000
39
42
39
8,000
40
43
40
9,000
41
44
41
10,000
42
45
42
SEE DETAIL “C”
Fig. 47 — Spark Gap Adjustment (48PG Only)
a48-5096
a48-4600
Summary of Contents for 48PG24
Page 68: ...68 Fig 14 Low Voltage Control Schematic 48PG20 28 Units without Humidi MiZer System a48 7627...
Page 69: ...69 Fig 15 Low Voltage Control Schematic 48PG20 28 Units with Humidi MiZer System a48 8227...
Page 70: ...70 Fig 16 Low Voltage Control Schematic 50PG20 28 Units without Humidi MiZer System a48 7778...
Page 71: ...71 Fig 17 Low Voltage Control Schematic 50PG20 28 Units with Humidi MiZer System a50 8101...
Page 72: ...72 Fig 18 Power Schematic Units without Humidi MiZer System a48 7628...
Page 73: ...73 Fig 19 Power Schematic Units with Humidi MiZer System a48 8228...
Page 74: ...74 Fig 20 Component Arrangement Units without Humidi MiZer System a48 8229...
Page 75: ...75 Fig 21 Component Arrangement Units with Humidi MiZer System a48 8230...
Page 105: ......