-- 26 --
NOTE
: Remove and discard bottom closure panel when bottom
inlet is used.
Step 6 -- Bottom Closure Panel
These furnaces are shipped with bottom enclosure panel installed
in bottom return-air opening. This panel MUST be in place when
side return air is used.
To remove bottom closure panel, perform following:
1. Tilt or raise furnace and remove 2 screws holding front
filler panel. (See Fig. 28.)
2. Rotate front filler panel downward to release holding tabs.
3. Remove bottom closure panel.
4. Reinstall front filler panel and screws.
Step 7 -- Gas Piping
Gas piping must be installed in accordance with national and
local codes. Refer to current edition of NFGC in the United
States. Canadian installations must be made in accordance with
NSCNGPIC and all authorities having jurisdiction.
Gas supply line should be a separate line running directly from
meter to furnace, if possible. Refer to Table 5 for recommended
gas pipe sizing. Risers must be used to connect to furnace and to
meter. Support all gas piping with appropriate straps, hangers,
etc. Use a minimum of 1 hanger every 6 ft (1.8 M). Joint
compound (pipe dope) should be applied sparingly and only to
male threads of joints. Pipe dope must be resistant to propane gas.
FILTER
FILTER
SUPPORT
FILTER
RETAINER
17
1
⁄
2
-IN. (444mm) WIDE
CASINGS ONLY:
INSTALL FIELD-SUPPLIED
FILTER FILLER STRIP
UNDER FILTER.
1
″
24
1
/
2
″
3
″
21-IN. (533mm) WIDE
CASINGS ONLY:
SUPPORT RODS (3)
EXTEND 1/4" (6mm) ON
EACH SIDE OF FILTER AND
REST ON CASING FLANGE
(76mm)
(533mm)
(25.4mm)
A08605
Fig. 27 --
Bottom Filter Arrangement
BOTTOM
CLOSURE
PANEL
FRONT FILLER
PANEL
A93047
Fig. 28 -- Removing Bottom Closure Panel
Table 5 – Maximum Capacity of Pipe *
NOMINAL
IRON PIPE
SIZE
IN. (MM)
INTERNAL
DIA.
IN. (MM)
LENGTH OF PIPE --- FT (M)
10
(3.0)
20
(6.0)
30
(9.1)
40
(12.1)
50
(15.2)
1/2 (12.7)
0.622
(158)
175
120
97
82
73
3/4 (19.0)
0.824
(20.9)
360
250
200
170
151
1 (25.4)
1.049
(26.6)
680
465
375
320
285
1-1/4
(31.8)
1.380
(35.0)
1400
950
770
660
580
1-1/2
(38.1)
1.610
(40.9)
2100
1460
1180
990
900
* Cubic ft of gas per hr for gas pressures of 0.5 psig (14---in. wc) or less and
a pressure drop of 0.5---in wc (based on a 0.60 specific gravity gas). Ref:
Table 9.2 NFGC.
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in fire, explosion,
personal injury, or death.
-- Connect gas pipe to furnace using a backup wrench to
avoid damaging gas controls.
-- Gas valve shutoff switch MUST be facing forward or
tilted upward.
-- 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.
-- Protect gas valve from water and debris. Gas valve inlet
and/or inlet piping must remain capped until gas supply line
is permanently installed to protect the valve from moisture
and debris. Also, install a sediment trap in the gas supply
piping at the inlet to the gas valve.
!
WARNING
Install a sediment trap in riser leading to furnace. Trap can be
installed by connecting a tee to riser leading to furnace so
straight-through section of tee is vertical. Then connect a capped
nipple into lower end of tee. Capped nipple should extend below
58MCB