Hot Surface Igniter; Gas Piping; Connection Of Gas Pipe - A.O. Smith CYCLONE Xi BTH 500A Owner's Manual

THE WATER HEATER IS POLARITY SENSITIVE. BEFORE
APPLYING ELECTRICITY TO THIS HEATER BE CERTAIN THAT
SUPPLY NEUTRAL WIRE TO GROUND CHECK INDICATES ZERO
VOLTAGE.

HOT SURFACE IGNITER

The Hot Surface Igniter is a device that ignites the main burner by
high temperature (>1800°F or >982°C). When 120VAC is applied
to the igniter, sufficient heat is generated to ignite the main burner.
Although improvements have been made to strengthen the igniter,
it is fragile and care must be taken when handling the igniter to
prevent breakage.

GAS PIPING

Contact your local gas service company to ensure that adequate
gas service is available and to review applicable installation codes
for your area.
Size the main gas line in accordance with Table 3. The figures
shown are for straight lengths of pipe at 0.5 in. W.C. (125Pa)
pressure drop, which is considered normal for low pressure
systems Note that fittings such as elbows and tees will add to the
pipe pressure drop.
DO NOT USE FLEXIBLE GAS PIPING.
TABLE 3. MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS
PER HOUR (Based upon a Pressure Drop of 0.5 inch Water Column
and 0.6 Specific Gravity Gas and max. gas pressure of 0.5 psig).
LENGTH NORMAL IRON PIPE SIZES (INCHES)
IN INPUT IN THOUSANDS BTU/HR
FEET 1 1/4" 1 1/2"
10 1400 2100
20 950 1460
30 770 1180
40
660 990
50 580 900
60 530 810
70 490 750
80 460 690
90 430 650
100 400 620
125 360 550
150 325 500
175 300 460
200 430
LENGTH NORMAL IRON PIPE SIZES (INCHES)
IN
METERS 1 1/4" 1 1/2"
3.0 410 615
6.1 278 428
9.1 225 346
12.2 193 290
15.2 170 264
18.3 155 237
21.3 143 220
24.4 135 202
27.4 126 190
30.5 117 182
38.1 105 161
45.7 95 146
53.3 88 135
61.0 126
CAUTION
CAUTION
2" 2 1/2" 3"
3960 6300 11000
2750 4360 7700
2200 3520 6250
1900 3000 5300
1680 2650 4750
1520 2400 4300
1400 2250 3900
1300 2050 3700
1220 1950 3450
1150 1850 3250
1020 1650 2950
950 1500 2650
850 1370 2450
800 1280 2280
INPUT IN KW
2" 2 1/2" 3"
1160 1845 3221
805 1277 2255
644 1031 1830
556 878 1552
492 776 1391
445 703 1259
410 659 1142
381 600 1083
357 571 1010
337 542 952
299 483 864
278 439 776
249 401 717
234 375 688
THE HEATER IS NOT INTENDED FOR OPERATION AT HIGHER
THAN 11.0" WATER COLUMN (2.74 Kpa) FOR NATURAL GAS AND
14.0" W.C. (3.49kPa) FOR PROPANE GAS SUPPLY PRESSURE.
HIGHER GAS SUPPLY PRESSURES REQUIRE SUPPLEMENTAL
REDUCING SERVICE REGULATION. EXPOSURE TO HIGHER
GAS SUPPLY PRESSURE MAY CAUSE DAMAGE TO THE GAS
CONTROLS WHICH COULD RESULT IN FIRE OR EXPLOSION.
IF OVERPRESSURE HAS OCCURRED SUCH AS THROUGH
IMPROPER TESTING OF GAS LINES OR EMERGENCY
MALFUNCTION OF THE SUPPLY SYSTEM THE GAS VALVE
MUST BE CHECKED FOR SAFE OPERATION. MAKE SURE THAT
THE OUTSIDE VENTS ON THE SUPPLY REGULATORS AND THE
SAFETY VENT VALVES ARE PROTECTED AGAINST BLOCKAGE.
THESE ARE PARTS OF THE GAS SUPPLY SYSTEM, NOT THE
HEATER. VENT BLOCKAGE MAY OCCUR DURING ICE STORMS.
IT IS IMPORTANT TO GUARD AGAINST GAS VALVE FOULING
FROM CONTAMINANTS IN THE GAS WAYS. SUCH FOULING
MAY CAUSE IMPROPER OPERATION, FIRE OR EXPLOSION.
IF COPPER SUPPLY LINES ARE USED THEY MUST BE
INTERNALLY TINNED AND CERTIFIED FOR GAS SERVICE.
BEFORE ATTACHING THE GAS LINE BE SURE THAT ALL GAS
PIPE IS CLEAN ON THE INSIDE.
TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS
SUPPLY LINE, A DIRT LEG (SOMETIMES CALLED A SEDIMENT
TRAP OR DRIP LEG) MUST BE INCORPORATED IN THE PIPING
(SEE FIG. 14). THE DIRT LEG MUST BE READILY ACCESSIBLE
AND NOT SUBJECT TO FREEZING CONDITIONS. INSTALL IN
ACCORDANCE WITH RECOMMENDATIONS OF SERVING GAS
SUPPLIERS. REFER TO THE NATIONAL FUEL GAS CODE NFPA
54 OR THE NATURAL GAS AND PROPANE INSTALLATION
CODE CAN/CSA-B149.1.
4"
23000
15800
12800
10900
9700
8800
8100
7500
7200
6700
6000

CONNECTION OF GAS PIPE

5500
5000
4600
1. When connecting gas pipe to unit, apply wrench to flange only.
Note: Do not use wrench on gas valve or gas bracket.
2. PERFORM THE GAS LEAK TEST ANY TIME WORK IS DONE
4"
ON A GAS SYSTEM TO AVOID THE POSSIBILITY OF FIRE OR
6735
EXPLOSION WITH PROPERTY DAMAGE, PERSONAL INJURY
4626
3748
OR LOSS OF LIFE.
3192
2840
The Gas Leak Test is performed as follows: Paint pipe connections
2577
upstream of gas control with a rich soap and water solution to test
2372
for leaks before operating main burner. Bubbles indicate gas leak.
2196
To stop leak, tighten pipe connections. After piping connections are
2108
checked, turn on main burner. With main burner in operation, paint
1962
pipe joints (including flanges), pilot gas tubing connections and
1757
1610 control inlet and outlet with rich soap and water solution. Bubbles
1464
indicate gas leak. To stop leak, tighten flange screws, joints and pipe
1347
connections. Replace part if leak can't be stopped.
5
WARNING
FIGURE 14.