Install Duct Connections; Configuring Units For Downflow (Vertical) Discharge - Bryant LEGACY 574D A Series Installation Instructions Manual

NOMINAL INTERNAL
IRON PIPE DIAMETER 10
SIZE (IN.) (IN.)
(3)
1/2 .622 175
3/4 .824 360
1 1.049 680
1--- 1/4 1.380 1400
1--- 1/2
1.610 2100
*Capacity of pipe in cu ft of gas per hr for gas pressure of 0.5 psig or less. Pressure drop of 0.5 ---
2 and National Fuel Gas Code NFPA 54/ANSI Z223.1.
{ This length includes an ordinary number of fittings.
OUT
Fig. 8 - - Sediment Trap
NOTE: Pressure test the gas supply system after the gas supply
piping is connected to the gas valve. The supply piping must be
disconnected from the gas valve during the testing of the piping
systems when test pressure is in excess of 0.5 psig. Pressure test the
gas supply piping system at pressures equal to or less than 0.5 psig.
The unit heating section must be isolated from the gas piping
system by closing the external main manual shutoff valve and
slightly opening the ground- -joint union.
WARNING
!
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal injury,
death and/or property damage.
- -Connect gas pipe to unit using a backup wrench to avoid
damaging gas controls.
- -Never purge a gas line into a combustion chamber. Never
test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for the detection of
leaks to check all connections.
- -Use proper length of pipe to avoid stress on gas control
manifold.
- -If a flexible connector is required or allowed by authority
having jurisdiction, black iron pipe shall be installed at
furnace gas valve and extend a minimum of 2 in. (51 mm)
outside furnace casing.
- -If codes allow a flexible connector, always use a new
connector. do not use a connector which has previously
serviced another gas appliance.
8. Check for gas leaks
factory- -installed gas lines after all piping connections have
Table 2 – Maximum Gas Flow Capacity*
20 30 40 50
(6) (9) (12) (15)
120 97 82 73
250 200 170 151
465 375 320 285
950 770 600 580
1460 1180 990 900
IN
TEE
NIPPLE
CAP
C99020
at the field- -installed and
LENGTH OF PIPE FT (m)†
60 70 80 90
(18) (21) (24) (27)
66 61 57 53
138 125 118 110
260 240 220 205
530 490 460 430
810 750 690 650
IN. W.C.
(based on a 0.60 specific gravity gas). Refer to Table
been completed. Use a commercially available soap solution
(or method specified by local codes and/or regulations).
Step 9 — Install Duct Connections
The unit has duct flanges on the supply- - and return- -air openings
on the side and bottom of the unit. For downshot applications, the
ductwork connects to the roof curb (See Fig. 3 and 4 for
connection sizes and locations).

Configuring Units for Downflow (Vertical) Discharge

WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Before installing or servicing system, always turn off main
power to system and install lockout tag. There may be
more than one disconnect switch.
1. Open all electrical disconnects before starting any service
work.
2. Remove horizontal (metal) duct covers to access vertical
(downflow) discharge duct knockouts in unit basepan.
3. Using Fig. 10 as a guide, proceed to cut out the downflow
duct panels.
4. Drill 1/2 in. (13 mm) diameter or larger holes in all four
corners of duct panels.
NOTE: On large chassis units remove sheet metal shields on
panels by using a screw driver to shear off retainers and discard.
5. On left and side supply duct opening side with keyhole or
single bladed hacksaw cut out panel along "V" groove.
6. On right side, with keyhole or single blade hacksaw, with
teeth facing up and starting from the front and moving to
the rear, cut along "V" groove.
7. Now with three sides cut, flex panel up and down to re-
move.
8. Replace side access panel and duct cover.
9. After completing unit conversion, perform all safety checks
and power up unit.
Alternate Method
1. Open all electrical disconnects and install lockout tag before
starting any service work.
2. Remove horizontal (metal) ductcovers to access vertical
(downflow) discharge duct knockouts in unit basepan. (See
Fig. 9.)
3. Leave top shipping crate on unit during this method.
4. Tip unit over on the front side (access panels) so the bottom
of the base pan is accessible.
5. Drill two holes diagonally opposed, of suitable size to ac-
commodate jigsaw or reciprocating saw. (See Fig. 10.)
10
100 125 150 175
(30) (38) (46) (53)
50 44 40 —
103 93 84 77
195 175 160 145
400 360 325 300
620 550 500 460
200
(61)
—
72
135
280
430