Reznor SHH (Indoor PreevA) Unit Installation Manual - Manual (Page 13)

Form I-PDH/SDH/PEH/SHH/PXH, Page 13
6.1.1 Gas Heat Section Gas Supply and Connections
WARNING:
This appliance is equipped for a maximum gas supply pressure of 1/2 psi, 3.5 kPa,
or 14 inches water column.
NOTE: Supply pressures higher than 1/2 psi require
installation of an additional service regulator external to the unit.
Pressure Testing Supply Piping
Test Pressure Above 1/2 PSI: Disconnect the heater and manual valve from the gas
supply which is to be pressure tested. Cap or plug the supply line.
Test Pressure Below 1/2 PSI: Before testing, close the manual valve on the heater.
All piping must be in accordance with requirements outlined in the National Fuel Gas
Code NFPA 54/ANSI Z223.1 (latest edition) or CSA B149.1 (latest edition) Natural
Gas and Propane Installation Code. Gas supply piping installation should conform with
good practice and with local codes.
These units for use with natural gas are orificed for gas having a heating value of 1000
(±50) BTU per cubic ft. If the gas at the installation does not meet this specification,
consult the factory for proper orifice.
Pipe joint compounds (pipe dope) shall be resistant to the action of liquefied petroleum
gas or any other chemical constituents of the gas being supplied.
Install a ground joint union and manual shutoff valve upstream of the unit control sys-
tem. The 1/8” plugged tapping in the shutoff valve provides connection for supply line
pressure test gauge. The National Fuel Gas Code requires the installation of a trap
with a minimum 3” (76mm) drip leg. Local codes may require a longer drip leg, typically
6” (152mm). See FIGURE 5.
6.0 Mechanical
6.1 Gas Heat
Section Piping
and Pressure
- Models PDH,
SDH, and SHH
NOTE: Gas conversion kits
are available for changing
SDH and PDH units with
a 1-stage or 2-stage gas
control option (AG1, AG2,
AG3, AG15, AG16, D12F)
from natural gas to propane
or propane to natural gas.
Conversion kits are not
available for a heater with
modulating burner control.
Contact your distributor,
representative, or the
factory for information.
TABLE 8 - Sizing Gas
Supply Lines
TABLE 9 - Gas
Connection Sizes
From Gas Supply
(horizontal or vertical)
Manual
shutoff
Drip
Leg
*To Gas
Valve
(inside the
cabinet)
*To Gas
Valve
(inside the
cabinet) Ground
Joint
Union
Drip
Leg
Ground Joint Union
Manual shutoff
FIGURE 5 -
Gas Connection
*See gas connection
location on dimension
drawing, FIGURE 2,
page 9.
PDH
and
SDH
75, 100,
125, 150,
175,
200
225,
250,
300,
350,
400A
SHH
130,
180
260,
350
Natural
Gas
1/2” 3/4”
Propane 1/2” 3/4”
NOTE: These are not
supply line sizes.
WARNING
All components of a gas supply system must be leak tested prior to placing the equipment
in service. NEVER TEST FOR LEAKS WITH AN OPEN FLAME. See Hazard Levels, page 2.
Capacity of Piping - Cubic Feet per Hour based on 0.3” w.c. Pressure Drop
Specific Gravity for Natural Gas -- 0.6 (Natural Gas -- 1000 BTU/Cubic Ft)
Specific Gravity for Propane Gas -- 1.6 (Propane Gas -- 2550 BTU/Cubic Ft)
Length of
Pipe
Diameter of Pipe
1/2” 3/4” 1” 1-1/4” 1-1/2” 2”
Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane
20’ 92 56 190 116 350 214 730 445 1100 671 2100 1281
30’ 73 45 152 93 285 174 590 360 890 543 1650 1007
40’ 63 38 130 79 245 149 500 305 760 464 1450 885
50’ 56 34 115 70 215 131 440 268 670 409 1270 775
60’ 50 31 105 64 195 119 400 244 610 372 1105 674
70’ 46 28 96 59 180 110 370 226 560 342 1050 641
80’ 43 26 90 55 170 104 350 214 530 323 990 604
90’ 40 24 84 51 160 98 320 195 490 299 930 567
100’ 38 23 79 48 150 92 305 186 460 281 870 531
125’ 34 21 72 44 130 79 275 168 410 250 780 476
150’ 31 19 64 39 120 73 250 153 380 232 710 433
175’ 28 17 59 36 110 67 225 137 350 214 650 397
200’ 26 16 55 34 100 61 210 128 320 195 610 372
Note: When sizing supply lines, consider possibilities of future expansion and increased requirements.
Refer to National Fuel Gas Code for additional information on line sizing.