Bryant 574D----A, Installation Instructions Manual

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15
REGULATOR
COVER SCREW
ADJUSTMENT
SCREW
REGULATOR SPRING
(PROPANE - WHITE)
NATURAL - SILVER)
GAS PRESSURE
REGULATOR
ADJUSTMENT
MANIFOLD
PRESSURE TAP
INLET
PRESSURE TAP
ON/OFF SWITCH
PLASTIC
(
A07751
Fig. 13 -- Single--Stage Gas Valve
If larger adjustments are required, change main burner orifices
following the recommendations of national and local codes.
NOTE
: All other appliances that use the same meter must be
turned off when gas flow is measured at the meter.
Proceed as follows:
1. Turn off gas supply to unit.
2. Remove pipe plug on manifold (See Fig. 11) and connect
manometer. Turn on gas supply to unit.
3. Record number of seconds for gas meter test dial to make
one revolution.
4. Divide number of seconds in Step 3 into 3600 (number of
seconds in one hr).
5. Multiply result of Step 4 by the number of cubic feet (cu ft)
shown for one revolution of test dial to obtain cubic feet (cu
ft) of gas flow per hour.
6. Multiply result of Step 5 by Btu heating value of gas to
obtain total measured input in Btuh. Compare this value
with heating input shown in Table 4 (Consult the local gas
supplier if the heating value of gas is not known).
EXAMPLE: Assume that the size of test dial is 1 cu ft, one
revolution takes 32 sec, and the heating value of the gas is 1050
Btu/ft
3
. Proceed as follows:
1. 32 sec. to complete one revolution.
2. 3600
÷
32 = 1.5.
3. 112.5 x 1 =112.5 ft
3
of gas flow/hr.
4. 112.5 x 1050 = 118,125 Btuh input.
If the desired gas input is 115,000 Btuh, only a minor change in the
manifold pressure is required.
Observe manifold pressure and proceed as follows to adjust gas
input:
1. Remove regulator cover screw over plastic adjustment
screw on gas valve (See Fig. 13).
2. Turn plastic adjustment screw clockwise to increase gas
input, or turn plastic adjustment screw counterclockwise to
decrease input (See Fig. 13). Manifold pressure must be
between 3.2 and 3.8 IN. W.C.
FIRE AND UNIT DAMAGE HAZARD
Failure to follow this warning could result in personal
injury or death and/or property damage.
Unsafe operation of the unit may result if manifold pressure
is outside this range.
!
WARNING
3. Replace regulator cover screw on gas valve (See Fig. 13).
4. Turn off gas supply to unit. Remove manometer from
pressure tap and replace pipe plug on gas valve. (See Fig.
11.) Turn on gas to unit and check for leaks.
Measure Manifold Pressure (Propane Units)
Refer to propane kit installation instructions for properly checking
gas input.
NOTE : For installations below 2,000 ft (610 m), refer to the unit
rating plate for proper propane conversion kit. For installations
above 2,000 ft (610 m), contact your distributor for proper propane
conversion kit.
Check Burner Flame
With control access panel (see Fig. 19) removed, observe the unit
heating operation. Watch the burner flames to see if they are light
blue and soft in appearance, and that the flames are approximately
the same for each burner. Propane will have blue flame (See Fig.
13). Refer to the Maintenance section for information on burner
removal.
Table 4 – Heating Inputs
HEATING INPUT
(BTUH)
NUMBER OF
GAS SUPPLY PRESSURE (IN. W.C.)
MANIFOLD PRESSURE
NUMBER OF
ORIFICES
Natural
{
Propane*
{
MANIFOLD PRESSURE
(IN. W.C.)
ORIFICES
Min Max Min Max Natural
{
Propane*†
40,000 2 4.0 13.0 11.0 13.0 3.2
∼
3.8 10.0
∼11.0
60,000
2 4.0 13.0 11.0 13.0 3.2
∼
3.8 10.0
∼11.0
90,000 3 4.0 13.0 11.0 13.0 3.2
∼
3.8 10.0
∼11.0
115,000 3 4.0 13.0 11.0 13.0 3.2
∼
3.8 10.0
∼11.0
130,000 3 4.0 13.0 11.0 13.0 3.2
∼
3.8 10.0
∼11.0
* When a unit is converted to propane, different size orifices must be used. See separate, natural---to---propane conversion kit instructions.
{
Based on altitudes from sea level to 2000 ft (610 m) above sea level. In the U.S.A. for altitudes above 2000 ft (610 m), reduce input rating 4 percent for each
additional 1000 ft (305 m) above sea level. In Canada, from 2000 ft (610 m) above sea level to 4500 ft (1372 m) above sea level, derate the unit 10 percent.
574D
--
--
A