A.O. Smith ***81-140, Установка, обслуживание, техническое обслуживание

Страница: 9 / 28

9
WARNING
THE HEATER IS NOT INTENDED FOR OPERATION AT HIGHER
THAN 10.5" W.C. - NATURAL GAS, 13.0" W.C. - PROPANE GAS
(1/2 POUND PER SQUARE INCH GAUGE) SUPPLY GAS
PRESSURE. HIGHER GAS 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.
DISCONNECT THE APPLIANCE AND ITS MAIN MANUAL GAS
SHUTOFF VALVE FROM THE GAS SUPPLY PIPING SYSTEM
DURING ANY SUPPLY PRESSURE TESTING EXCEEDING 1/2
PSIG. GAS SUPPLY LINE MUST BE CAPPED WHEN
DISCONNECTED FROM THE HEATER. FOR TEST
PRESSURES OF 1/2 PSIG OR LESS, THE APPLIANCE NEED
NOT BE DISCONNECTED, BUT MUST BE ISOLATED FROM
THE SUPPLY PRESSURE TESTING BY CLOSING THE MAIN
MANUAL GAS SHUT OFF VALVE.
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 4. The figures
shown are for iron pipe or equivalent at 0.5 in. w.c. pressure
drop, which is considered normal for low pressure systems.
Note that an excess number of fittings such as elbows and tees
will add to the pipe pressure drop. No additional allowance is
necessary for an ordinary number of fittings.
IF COPPER SUPPLY LINES ARE USED THEY MUST BE
INTERNALLY TINNED AND CERTIFIED FOR GAS SERVICE.
IT IS IMPORTANT TO GUARD AGAINST GAS VALVE FOULING
FROM CONTAMINANTS IN THE GAS WAYS. SUCH FOULING
MAY CAUSE IMPROPER OPERATION, FIRE OR EXPLOSION.
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 DRIP LEG (SOMETIMES CALLED DIRT LEG)
MUST BE INCORPORATED IN THE PIPING. SEE FIG. 8. THE
DRIP LEG MUST BE READILY ACCESSIBLE, REFER TO FIG. 8,
AND NOT SUBJECT TO FREEZING CONDITIONS. INSTALL IN
ACCORDANCE WITH RECOMMENDATIONS OF SERVICING
GAS SUPPLIERS. REFER TO THE NATIONAL FUEL GAS CODE
(LATEST VERSION).
To prevent damage, care must be taken not to apply too much
torque when attaching gas supply pipe to gas valve inlet.
TABLE 4
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 .5 psig)
LENGTH NOMINAL IRON PIPE SIZE (INCHES)
IN FEET 1/2 3/4 1 1 1/4 1 1/2 2 2 1/2 3 4
10 175 360 680 1,400 2,100 3,950 6,300 11,000 23,000
20 120 250 465 950 1,460 2,750 4,350 7,700 15,800
30 97 200 375 770 1,180 2,200 3,520 6,250 12,800
40 82 170 320 660 990 1,900 3,000 5,300 10,900
50 73 151 285 580 900 1,680 2,650 4,750 9,700
60 66 138 260 530 810 1,520 2,400 4,300 8,800
70 61 125 240 490 750 1,400 2,250 3,900 8,100
80 57 118 220 460 690 1,300 2,050 3,700 7,500
90 53 110 205 430 650 1,220 1,950 3,450 7,200
100 50 103 195 400 620 1,150 1,850 3,250 6,700
125 44 93 175 360 550 1,020 1,650 2,950 6,000
150 40 84 160 325 500 950 1,500 2,650 5,500
175 37 77 145 300 460 850 1,370 2,450 5,000
200 35 72 135 280 430 800 1,280 2,280 4,600
Apply joint compounds (pipe dope) sparingly and only to the male
threads of pipe joints. Do not apply compound to the first two
threads. Use joint compounds resistant to the action of liquefied
petroleum gases.
BEFORE PLACING THE HEATER IN OPERATION, CHECK FOR
GAS LEAKAGE. USE SOAP AND WATER SOLUTION, OR
OTHER MATERIAL ACCEPTABLE FOR THE PURPOSE IN
LOCATING GAS LEAKS. DO NOT USE MATCHES, CANDLES,
FLAME OR OTHER SOURCES OF IGNITION FOR THIS
PURPOSE.
POWER BURNER ASSEMBLY, GAS MANIFOLD AND SUGGESTED
INLET PIPING - FIGURE 8
HEATER WIRING INSTRUCTIONS
The power burner should be wired to the heater as shown in
Figure 9. The model’s rating plate (or see Table 2) provides the
electrical information needed to size the complete heater branch
supply circuit.
All electrical work must be installed in accordance with the latest
version of the National Electrical Code and local requirements.
When installed, the appliance must be electrically grounded in
accordance with local codes or, in the absence of local codes,
with the latest version of the National Electrical Code,
ANSI/NFPA 70.