Carrier 58DXT - Page 8

Never purge a line into a combustion chamber. Never use
matches, candles, flame, or other sources of ignition to check
for gas leakage. Use a soap-and-water solution to check for
gas leaks. A failure to follow this warning could result in fire,
explosion, personal injury, or death.
Piping should be pressure tested in accordance with local and
national plumbing and gas codes before furnace has been attached.
If test pressure exceeds 0.5 psig (14-in. wc), the gas supply pipe
must be disconnected from furnace and capped before pressure
test. If test pressure is equal to or less than 0.5 psig (14-in. wc),
turn off electric shutoff switch located on the gas valve before test.
It is recommended that ground joint union be loosened before
pressure testing.
Joint compounds (pipe dope) should be applied sparingly and only
to male threads of joints. This pipe dope must be resistant to action
of propane gas.
Install accessible manual shutoff valve upstream of furnace gas
controls and within 72 in. of furnace. A 1/8-in. NPT plugged
tapping is provided on gas value for test gage connection.
Installation of additional 1/8-in. NPT plugged tapping, accessible
for test gage connection, installed immediately upstream of gas
supply connection to furnace and downstream of manual shutoff
valve is not required. Place ground joint union between gas control
manifold and manual shutoff.
Fig. 6—Furnace, Plenum, and Subbase Installed on
a Combustible Floor
A96285
DOWNFLOW
SUBBASE
SHEET METAL
PLENUM
FLOOR
OPENING
FURNACE
(OR COIL CASING
WHEN USED)
COMBUSTIBLE
FLOORING
Fig. 7—Furnace, Plenum, and Coil Assembly or Coil
Box Installed on a Combustible Floor
A96284
CD5 OR CK5
COIL ASSEMBLY
OR KCAKC
COIL BOX
FURNACE
SHEET METAL
PLENUM
FLOOR
OPENING
COMBUSTIBLE
FLOORING
Table 4—Maximum Capacity of Pipe*
NOMINAL
IRON PIPE
SIZE (IN.)
INTERNAL
DIAMETER
(IN.)
LENGTH OF PIPE (FT)
10 20 30 40 50
1/2 0.622 175 120 97 82 73
3/4 0.824 360 250 200 170 151
1 1.049 680 465 375 320 285
1-1/4 1.380 1400 950 770 660 580
1-1/2 1.610 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
supply line pressure drop of 0.5-in. wc (based on a 0.60 specific gravity gas).
Ref: Table 10-2, NFPA 54-1996.
Fig. 8—Downflow Filter Arrangement
A88486
RETURN-AIR
PLENUM
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AIRFLOW
ACCESS DOOR
INSTALLATION
POSITION
OF FILTERS
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