Check Inlet Gas Supply - Lochinvar FTxl 400 Installation & Operation Manual

7
Gas connections
Table 7A Natural Gas Pipe Size Chart
Capacity of Schedule 40 Metallic Pipe in Cubic Feet of Natural Gas Per Hour
Pipe
Size
10 20
(Inches)
1/2 131 90
3/4 273 188
1 514 353
1 1/4 1,060 726
1 1/2 1,580 1,090
2 3,050 2,090
2 1/2 4,860 3,340
3 8,580 5,900
4 17,500 12,000

Check inlet gas supply

CSA or UL listed fl exible gas connections
NOTICE
are acceptable, but you must exercise
caution to ensure that the line has adequate
capacity to allow your boiler to fi re at full
rate. Consult with local codes for proper
installation or service procedures.
DO NOT adjust gas valve outlet pressure.
WARNING
Attempting to alter the gas valve outlet
pressure could result in damage to the valve,
causing potential severe personal injury,
death, or substantial property damage.
The gas piping must be sized for the proper fl ow and length of
pipe, to avoid excessive pressure drop. Both the gas meter and
the gas regulator must be properly sized for the total gas load.
If you experience a pressure drop greater than 1 inch w.c.
(249 Pa), the meter, regulator, or gas line is undersized or in
need of service. Perform the steps below when checking inlet
gas supply:
1. Turn the main power switch to the "OFF" position.
2. Shut off gas supply at the manual gas valve in the gas
piping to the appliance.
3. On Models 400 - 500 loosen the set screw one (1) full turn
from inside the pressure tap on top of the gas valve. On
Models 600 - 850 remove the 1/8" (3 mm) pipe plug on the
inlet fl ange to the valve and install a suitable 1/8" (3 mm)
fi tting (fi eld supplied) for the manometer tubing. Place
the tubing of the manometer over the tap once the set
screw is loosened or the 1/8" (3 mm) fi tting is installed
(depending on model) as shown in FIG.'s 7-5 and 7-6 on
page 51.
50
(based on .60 specifi c gravity, 0.30" w.c. pressure drop)
Length of Pipe in Straight Feet
30 40 50 60
72 62 55 N/A
151 129 114 104
284 243 215 195
583 499 442 400
873 747 662 600
1,680 1,440 1,280 1,160
2,680 2,290 2,030 1,840
4,740 4,050 3,590 3,260
9,660 8,270 7,330 6,640
Installation & Operation Manual
70 80 90 100
N/A N/A N/A N/A
95 89 83 79
179 167 157 148
368 343 322 304
552 514 482 455
1,060 989 928 877
1,690 1,580 1,480 1,400
3,000 2,790 2,610 2,470
6,110 5,680 5,330 5,040
4. Slowly turn on the gas supply at the fi eld installed
manual gas valve.
5. Turn the power switch to the "ON" position.
6. Adjust the temperature set point on the control panel of
the SMART SYSTEM control module to call for heat.
7. Observe the gas supply pressure as the burner fi res at
100% of rated input. Percent of burner input will be
displayed on the control panel.
8. Ensure inlet pressure is within specifi ed range.
Minimum and maximum gas supply pressures are
specifi ed in this section of the manual.
9. If gas supply pressure is within normal range and no
adjustments are needed, proceed on to Step 11.
10. If the gas pressure is out of range, contact the gas utility,
gas supplier, qualifi ed installer or service agency to
determine the necessary steps to provide proper gas
pressure to the control.
11. Turn the power switch to the "OFF" position.
12. Shut off the gas supply at the manual gas valve in the gas
piping to the appliance.
13. Remove the manometer from the pressure tap on top of
the gas valve. On Models 400 - 500 re-tighten the set
screw inside the pressure tap. On Models 600 - 850
remove the 1/8" (3 mm) fi eld supplied fi tting and
reinstall the pipe plug removed in Step 3.
125 150 175 200
N/A N/A N/A N/A
70 63 58 N/A
131 119 109 102
269 244 224 209
403 366 336 313
777 704 648 602
1,240 1,120 1,030 960
2,190 1,980 1,820 1,700
4,460 4,050 3,720 3,460