Carrier 48SX024-048 - Manual (Page 13)

UNITS WITH OPTIONAL BASE RAIL - Lifting holes
are provided in optional base rail as shown in Fig. 12. Op­
erating weights are shown in Tables 1 and 2. Refer to Rig­
ging instructions on unit.
Protective wood support must be removed from unit be­
fore unit is mounted to curb. Remove 4 screws that secure
support above rigging holes in rails. Slide support out through
rectangular hole in rail. See Fig. 13.
Step 6 — Connect Condensate Drain
NOTE: When installing condensate drain connection be sure
to comply with local codes and restrictions.
Model 48SS,SX disposes of condensate water through a
¥4 in. NPT fitting which exits through the compressor ac­
cess panel. See Fig. 2-9 for location.
Install field-supplied condensate trap at end of conden­
sate connection to ensure proper drainage. See Fig. 14.
V'MIN.
If the installation requires draining the condensate water
away from the unit, install a 2-in. trap at the condensate
connection to ensure proper drainage. Make sure that the
outlet of the trap is at least 1 in. lower than the drain-pan
condensate connection to prevent the pan from overflow­
ing. Prime the trap with water. Connect a drain tube using
a minimum of y4-in. PVC or V4-m. copper pipe (all field-
supplied) at the outlet end of the 2-in. trap. Do not under­
size the tube. Pitch the drain tube downward at a slope of at
least one in. for every 10 ft of horizontal run. Be sure to
check the drain tube for leaks.
Condensate water can be drained directly onto the roof in
rooftop installations (where permitted) or onto a gravel apron
in ground-level installations. When using a gravel apron,
make sure it slopes away from the unit.
Step 7 — Install Flue Hood — The flue hood as­
sembly is shipped screwed to the control box in the burner
compartment. Remove the burner access panel to locate the
assembly.
A CAUTION
The venting system is designed to ensure proper vent­
ing. The flue hood assembly must be Installed as indi­
cated in this section of the unit installation instructions.
Install the flue hood as follows:
1. Remove from shipping location. Place vent cap assem­
bly over flue panel. Orient screw holes in vent cap with
holes in the flue panel.
2. Secure flue hood to flue panel by inserting a single
screw on the right side, the left side, and the top of flue
hood.
Step 8 — Install Gas Piping — The gas supply pipe
enters the unit through the access hole provided. The gas
connection to the unit is made to the '/
2 -in. FPT gas inlet on
the manual shutoff or gas valve.
Install a gas supply line that runs to the heating section.
Refer to Table 3 and the National Fuel Gas Code (NFGC)
for gas pipe sizing. Do not use cast-iron pipe. It is recom­
mended that a black iron pipe is used. Check the local util­
ity for recommendations concerning existing lines. Size gas
supply piping for 0.5 in. wg maximum pressure drop. Never
use pipe smaller than the Vi-in. FPT gas inlet on the unit
gas valve.
For natural gas applications, the gas pressure at unit gas
connection must not be less than 4.0 in. wg or greater than
13 in. wg while the unit is operating. For propane applica­
tions, the gas pressure must not be less than 4.0 in. wg or
greater than 13 in. wg at the unit connection.
When installing the gas supply line, observe local codes
pertaining to gas pipe installations. Refer to the NFGC ANSI
(American National Standard’s Institute) Z223.1-1988 NFPA
(National Fire Protection Association) latest edition (in
Canada, CAN/CGA B149.1, (2)-M86). In the absence of
local building codes, adhere to the following pertinent
recommendations :
1. Avoid low spots in long runs of pipe. Grade all pipe
'/4 inch in every 15 ft to prevent traps. Grade all hori­
zontal runs downward to risers. Use risers to connect to
heating section and to meter.
2. Protect all segments of piping system against physical
and thermal damage. Support all piping with appro­
priate straps, hangers, etc. Use a minimum of one hanger
every 6 ft. For pipe sizes larger than
'/2 in., follow rec­
ommendations of national codes.
3 Apply joint compound (pipe dope) sparingly and only to
male threads of joint when making pipe connections. Use
only pipe dope that is resistant to action of liquefied
petroleum gases as specified by local and/or national codes.
Never use Teflon tape.
4. Install sediment trap in riser leading to heating section
per Fig. 15. This drip leg functions as a trap for dirt and
condensate.
5. Install an accessible, external, manual main shutoff valve
in gas supply pipe within 6 ft of heating section.
6. Install ground-joint union close to heating section be­
tween unit manual shutoff and external manual main shut­
off valve.
7. Pressure-test all gas piping in accordance with local and
national plumbing and gas codes before connecting pip­
ing to unit.
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 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.
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