Rheem 801C Series, Руководство по установке

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25
GAS SUPPLY (cont .)
IMPORTANT: ENSURE that the furnace gas valve is not to be
subjected to high gas line supply pressures .
DISCONNECT the furnace and its individual manual gas stop
from the gas supply piping during any pressure testing that
exceeds 1/2 PSIG . (3 .48 kPa) .
Natural gas supply pressure must be 5” to 10.5” w.c. LP
gas supply pressure must be 11” to 13” w.c. This pressure
must be maintained with all other gas-fired appliances in
operation .
The minimum gas supply pressure to the gas valve for proper
furnace input adjustments is 5” w .c . for natural gas, however 6”
to 7” is recommended . The minimum gas supply pressure is 11”
w .c . for LP gas .
GAS VALVE
This furnace has a 24-volt gas valve . It has ports for measuring
supply and manifold gas pressure . The valve body contains a
pressure regulator to maintain proper manifold gas pressure .
A control switch is on the valve body . It can be set to only the
“ON” or “OFF” positions . The gas valve is a slow-opening
valve . See Figures 20A and 20B .
When energized, it takes 2 to 3 seconds to fully open .
GAS PRESSURE
!
CAUTION
ELEVATIONS ABOVE 2000 FT . REQUIRE THAT
THE FURNACE INPUT RATING BE ADJUSTED
AND THAT THE SIZE OF THE BURNER ORIFICES
BE RECALCULATED BASED ON ELEVATION AND
GAS HEATING VALUE . THE BURNER ORIFICES
MAY (OR MAY NOT) NEED TO BE CHANGED . SEE
THE SECTION TITLED “HIGH ALTITUDE INSTALLA-
TIONS” OF THIS BOOK FOR INSTRUCTIONS .
FIGURE 20A
TYPICAL GAS VALVE (HONEYWELL)
REGULATOR CAP
!
WARNING
NEVER PURGE A GAS LINE INTO THE COMBUSTION
CHAMBER . NEVER USE MATCHES, FLAME OR ANY
IGNITION SOURCE FOR CHECKING LEAKAGE . FAIL-
URE TO ADHERE TO THIS WARNING CAN CAUSE
A FIRE OR EXPLOSION RESULTING IN PROPERTY
DAMAGE, PERSONAL INJURY OR DEATH .
TO CHECK FOR GAS LEAKAGE, USE AN AP-
PROVED CHLORIDE-FREE SOAP AND WATER
SOLUTION, OR OTHER APPROVED METHOD .
TABLE 6
NATURAL GAS PIPE CAPACITY TABLE (CU . FT ./HR .)
Capacity of gas pipe of different diameters and lengths in cu. ft. per hr. with pressure drop of 0.3 in. and specific gravity of
0.60 (natural gas).
Nominal Length of Pipe, Feet
Iron Pipe
Size, Inches 10 20 30 40 50 60 70 80
1/2 132 92 73 63 56 50 46 43
3/4 278 190 152 130 115 105 96 90
1 520 350 285 245 215 195 180 170
1-1/4 1,050 730 590 500 440 400 370 350
1-1/2 1,600 1,100 890 760 670 610 560 530
After the length of pipe has been determined, select the pipe size which will provide the minimum cubic feet per hour re-
quired for the gas input rating of the furnace. By formula:
Gas Input of Furnace (BTU/HR)
Cu. Ft. Per Hr. Required = Heating Value of Gas (BTU/FT
3
)
The gas input of the furnace is marked on the furnace rating plate. The heating value of the gas (BTU/FT
3
) may be determined
by consulting the local natural gas utility or the LP gas supplier.
Gas Supply
FIGURE 20B
WHITE RODGERS GAS VALVE
REGULATOR
CAP