25
3
Gas connections
Installation & Service Manual
Gas supply
Verify appliance is supplied with type gas specified on
rating plate. This appliance is orificed for operation up to
2000 feet altitude. The appliance will be derated 4% per
1000 feet above 2000 feet elevation. Consult the factory for
installations above 2000 feet elevation. Field conversions
for operation at high altitude must be performed by
factory authorized personnel only. The appliance will be
marked to indicate suitability for high altitude operation.
INLET GAS PRESSURE:
Measured at the inlet pressure
tap located upstream of the combination gas valve.
Maximum inlet gas pressure must not exceed the value
specified. Minimum value listed is for the purposes of
input adjustment.
MANIFOLD PRESSURE:
Measured at the pressure tap
on the downstream side of the combination gas valve. The
gas regulator on the appliance’s combination gas valve(s) is
adjustable to supply proper manifold pressure for normal
operation. If adjustment of regulator pressure is required,
see
Manifold Adjustment Procedure
.
Do not increase
regulator pressure beyond specified pressure setting.
TABLE 3A
INLET GAS PRESSURE
Natural Gas
LP
Max. Water
Column
(Inches)
10.5"
13"
Min. Water
Column
(Inches)
4.0"
8"
TABLE 3B
NET MANIFOLD PRESSURE
Btu/hr
Input
150,000 -
300,000
Nat. Gas
Regulator Setting
1.8" w.c.
13"
Btu/hr
Input
150,000 -
300,000
LP Gas Regulator
Setting
4.6" w.c.
8"
TABLE 3C
MULTIPLE APPLIANCE INSTALLATIONS GAS PIPING SIZE CHART
Nominal Iron
Pipe Size, IN.
Length of Pipe in Straight Feet
10
20
30
40
50
60
70
80
90
100
125
150
175
200
3/4
369
256
205
174
155
141
128
121
113
106
95
86
79
74
1
697
477
384
328
292
267
246
256
210
200
179
164
149
138
1 1/4
1,400
974
789
677
595
543
502
472
441
410
369
308
308
287
1 1/2
2,150
1,500
1,210
1,020
923
830
769
707
666
636
564
472
472
441
2
4,100
2,820
2,260
1,950
1,720
1,560
1,440
1,330
1,250
1,180
1,100
974
871
820
2 1/2
6,460
4,460
3,610
3,100
2,270
2,460
2,310
2,100
2,000
1,900
1,700
1,540
1,400
1,300
3
11,200
7,900
6,400
5,400
4,870
4,870
4,000
3,800
3,540
3,300
3,000
2,720
2,500
2,340
4
23,500
16,100
13,100
11,100
10,000
10,000
8,300
7,690
7,380
7,380
6,150
5,640
5,130
4,720
Maximum Capacity of Pipe in Thousands of Btu/hr per hour for gas pressures of 14 Inches Water Column (0.5 PSIG) or less and
a pressure drop of 0.5 Inch Water Column (Based on NAT GAS, 1025 Btu/hr per Cubic Foot of Gas and 0.60 Specific Gravity).
Gas pressure test
1. The appliance must be disconnected from the gas supply
piping system during any pressure testing of that system
at a test pressure in excess of 1/2 PSIG (3.5 kPa).
2. The appliance must be isolated from the gas supply
piping system by closing a manual shutoff valve during
any pressure testing of the gas supply piping system at
test pressures equal to or less than 1/2 PSIG (3.5 kPa).
3. The appliance and its gas connection must be leak-tested
before placing it in operation.
TABLE 3D
SINGLE APPLIANCE INSTALLATIONS
SUGGESTED GAS PIPE SIZE
Input
Btu/hr
DISTANCE FROM METER
150,000
1"
1"
1 1/4"
1 1/2"
1 1/2"
199,999
1"
1"
1 1/4"
1 1/2"
2"
250,000
1"
1 1/4"
1 1/4"
1 1/2"
2"
300,000
1 1/4"
1 1/2"
1 1/2"
1 1/2"
2"
Summary of Contents for Efficiency-Pac EW 150 -- 300
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