Lochinvar Shield SNR200-100 - Manual (Page 41)

41
Nominal
Iron Pipe
Size (Inches)
Natural Gas Pipe Capacity Chart
Length of Pipe in Straight Feet for 1/2 PSI
10 20 30 40 50 60 70 80 90 100 125 150 175 200
1/2 175 120 97 82 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
3/4 369 256 205 174 155 141 128 121 113 106 95 86 79 74
1 697 477 384 328 292 267 246 236 210 200 179 164 149 138
1-1/4 1400 974 789 677 595 543 502 472 441 410 369 333 308 287
1-1/2 2150 1500 1210 1020 923 830 769 707 666 636 564 513 472 441
2 4100 2820 2260 1950 1720 1560 1440 1330 1250 1180 1100 974 871 820
2-1/2 6460 4460 3610 3100 2720 2460 2310 2100 2000 1900 1700 1540 1400 1300
3 11200 7900 6400 5400 4870 4410 4000 3800 3540 3330 3000 2720 2500 2340
4 23500 16100 13100 11100 10000 9000 8300 7690 7380 6870 6150 5640 5130 4720
Shield water heaters are typically shipped ready to fire on natural gas. Check the water heater rating plate to
determine which fuel the water heater is set for. In order to operate on LP gas contact the factory, an orifice
MUST BE installed or a gas valve adjustment MUST BE made. Failure to comply could result in severe
personal injury, death, or substantial property damage.
Table 7A Natural Gas Pipe Size Chart
The gas piping must be sized for the proper flow 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.,
the meter, regulator, or gas line is undersized or in need of
service. Perform the steps below when checking inlet gas
supply:
1. Disconnect power from the appliance.
2. Shut off gas to the appliance.
3. Loosen the set screw one (1) full turn from inside the
pressure tap on top of the gas valve. Place the tubing of
the manometer over the tap once the set screw is
loosened as shown in FIG.’s 7-4 thru 7-6.
4. Slowly turn on the gas supply at the field installed
manual gas valve.
ƽ WARNING
5. Reconnect power to the appliance.
6. Adjust the temperature set point on the control panel of
the electronic control module to call for heat.
7. Observe the gas supply pressure as the burner fires at
100% of rated input. Percent of burner input will be
displayed on the control panel.
8. Ensure inlet pressure is within specified range.
Minimum and maximum gas supply pressures are
specified 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, qualified installer or service agency to
determine the necessary steps to provide proper gas
pressure to the control.
11. Disconnect power from the appliance.
12. Shut off the gas to the appliance.
13. Remove the manometer from the pressure tap on top of
the gas valve. Re-tighten the set screw inside the pressure
tap.
Check inlet gas supply
NOTICE
CSA or UL listed flexible gas connections
are acceptable, but you must exercise
caution to ensure that the line has adequate
capacity to allow your water heater to fire
at full rate. Consult with local codes for
proper installation or service procedures.
DO NOT adjust or attempt to measure
gas valve outlet pressure. The gas valve is
factory-set for the correct outlet pressure.
This setting is suitable for natural gas
and propane (when configured for LP),
requiring no field adjustment. Attempting
to alter or measure the gas valve outlet
pressure could result in damage to the
valve, causing potential severe personal
injury, death, or substantial property
damage.
ƽ WARNING
7
Gas connections
(continued)
ƽ WARNING
When re-tightening the set screw, be sure to
tighten securely to prevent gas leaks.
Do not check for gas leaks with an open
flame -- use the bubble test. Failure to
use the bubble test or check for gas leaks
can cause severe personal injury, death, or
substantial property damage.
14. Reconnect gas to the appliance.
15. Reconnect power to the appliance.
16. Adjust the temperature set point on the control panel of
the electronic control module to the desired water
temperature so the appliance will call for heat.
Installation & Service Manual TM