Carrier 48KHA - Manual (Page 5)

Step 2 — Make Gas Piping Connections — A
manual shutoff valve is shipped loose in the burner
compartment or blower compartment. Connect one
end of a field-supplied 1/2-in. straight nipple to the
gas valve inlet. Connect the other end of the nipple
to the manual shutoff valve as shown in Fig. 6. The
gas supply pipe enters unit through access hole pro­
vided. See Fig. 4 for location. The gas connection to
unit is made to the 1/2-in. FPT gas inlet on manual
shutoff. See Fig. 6 for inlet location.
Install a separate gas supply line that runs directly
from meter to heating section. Do not use cast-iron
pipe. Check local utility for recommendations con­
cerning existing lines. Choose a supply pipe that is
large enough to keep pressure loss as low as prac­
tical. Never use pipe smaller than the 112-in. FPT
gas inlet on unit manual shutoff.
When installing gas supply line, observe local
codes pertaining to gas pipe installations. Refer to
National Fuel Gas Code, NFPA 54-1980/ANSI
Z223.1-1980 in absence of local building codes.
Adhere to following pertinent recommendations:
1
2
3
4
5
6
7
Control Transformer 9
Compressor Contactor 10
Ground Lug
Dual Run Capacitor 11
(for compressor and 12
condenser fan motor) 13
Gas Valve
1/2-in Nipple 14
Gas Pipe
Entrance Hole
15
Gas Inlet 16
Pressure Tap 17
Manual Shutoff
Regulator, Adjustment
Cover Screw
Electronic Control Head
Secondary-Air Shield
Low-Voltage Pigtail
Leads
Blower Motor Run
Capacitor
Heating Relay
Cooling Relay
Combustion Air Shroud
Fig. 6 — Model 48KLA036 — Side View
(Partial) with Access Doors Removed
1. Avoid low spots in long runs of pipe. Grade all
pipe I /4 in. in every 15 ft to prevent traps. Grade
all horizontal 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 appropriate hangers, etc. Use a minimum of
one hanger in every 6 feet. For pipe sizes larger
than 1 / 2 in., follow recommendations 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 speci­
fied by local and/or national codes. Never use
pipe thread tape.
4. Install a sediment trap in riser leading to the heat­
ing section. See Fig. 7. This drip leg functions as a
trap for dirt and condensate. Install trap where
condensate cannot freeze. Install this sediment
trap by connecting a piping tee to riser leading to
heating section, so that straight-through section
of tee is vertical. Then, connect capped nipple
into lower end of tee. Extend capped nipple
below level of gas controls.