Trane Foundation GBC180 Installation, Operation And Maintenance Manual page 24

I I n n s s t t a a l l l l a a t t i i o o n n
Table 4. Gas heater operating data
Heating Input Rate
—Btu/h
Minimum Supply Gas Pressure Natural/LP
Manifold Gas Pressure
(a)
Combustion Blower Suction Pressure (1
Combustion Blower Suction Pressure (2
Minimum Flame Sensing Current
Normal Sensing Current Range
Flue Gas Temperature Rise Above Ambient
Flue Gas Content - % CO
2
Minimum Supply Air Temperature Across Heat Exchanger
(a) Staged gas heat units have a positive pressure gas valve. Never adjust the staged gas pressure valve to a negative pressure.
(b) A voltage reading across pens (V+) and (V-) is equatable to the flame sensing current. One volt equals one micro amp.
Table 5. Piping
Length of Pipe (ft)
15
30
45
60
75
Note: Capacity of Pipe of Different Diameters and Lengths in Cu. Ft. Per Hr. with Pressure Drop of 0.3" and Specific Gravity of 0.60.
Table 6. Specific gravity multipliers
Specific Gravity
Figure 20. Schematic diagram for field gas piping to units
1/8" NPT Test Plug
Gas Supply Line
Gas shuttoff (Field Supplied
outside unit cabinet.)
24
st
Stage)
nd
Stage)
(b)
1/2" Pipe 3/4" Pipe
76 176
52 120
43 99
38 86
77 155
0.50
0.55
0.60
0.65
Field supplied ground
Union
Drip Leg
125,000 180,000
4.5/11.0 4.5/11.0
3.5
-1.3 to -1.7 -1.3 to -1.7
-1.3 to -1.7 -1.3 to -1.7
8.0 to 16 Micro Amps DC
7.0% to 8.0% (Natural Gas)
7.5% to 9.0% (Propane)
Iron Pipe Size (IPS) Inches
1" Pipe
345
241
199
173
345
6" MIN
To Gas Train
Unit Access Hole
225,000
4.5/11.0
3.9 3.6
-1.1 to -1.5
-1.1 to -1.5
5.0 Micro Amps DC
230 to 300 F
40° F
1¼" Pipe 1½" Pipe
750
535
435
380
545
Multipliers
1.10
1.04
1.00
0.96
250,000
4.5/11.0
3.5
-1.1 to -1.5
-1.1 to -1.5
1220
850
700
610
RT-SVX51H-EN