Carrier WeatherMaker 48TC 04, Installation Instructions Manual

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4. 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 pip-
ing must be disconnected from the gas valve during the test-
ing of the piping systems when test pressure is in excess of
0.5 psig (3450 Pa). Pressure test the gas supply piping sys-
tem at pressures equal to or less than 0.5 psig (3450 Pa).
The unit heating section must be isolated from the gas pip-
ing system by closing the external main manual shutoff
valve and slightly opening the ground-joint union.
Check for gas leaks at the field-installed and factory-in-
stalled gas lines after all piping connections have been com-
pleted. Use soap-and-water solution (or method specified by
local codes and/or regulations).
NOTE: If orifice hole appears damaged or it is suspected to
have been re-drilled, check orifice hole with a numbered
drill bit of correct size. Never re-drill an orifice. A burr-free
and squarely aligned orifice hole is essential for proper
flame characteristics. See Fig. 20.
Fig. 20 — Orifice Hole
Step 11 — Install External Condensate Trap
and Line —
The unit has one 3 /
4
-in. condensate drain con-
nection on the end of the condensate pan and an alternate con-
nection on the bottom. See Fig. 21. Unit airflow configuration
does not determine which drain connection to use. Either drain
connection can be used with vertical or horizontal applications.
To use the alternate bottom drain connection, remove the
red drain plug from the bottom connection (use a 1 /
2
-in. square
socket drive extension) and install it in the side drain connec-
tion.
Fig. 21 — Condensate Drain Pan (Side View)
The piping for the condensate drain and external trap can be
completed after the unit is in place. See Fig. 22.
NOTE: If the alternate bottom drain is not used check the
drain plug for tightness prior to setting the unit on the roof
curb.
Fig. 22 — Condensate Drain Piping Details
All units must have an external trap for condensate drain-
age. Install a trap at least 4-in. (102 mm) deep and protect
against freeze-up. If drain line is installed downstream from the
external trap, pitch the line away from the unit at 1-in. per 10 ft
(25 mm in 3 m) of run. Do not use a pipe size smaller than the
unit connection ( 3 /
4
-in.).
Step 12 — Make Electrical Connections
NOTE: Field-supplied wiring shall conform with the limita-
tions of minimum 63°F (33°C) rise.
WARNING
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 specifi-
cally for the detection of leaks to check all connec-
tions.
• Use proper length of pipe to avoid stress on gas con-
trol manifold.
BURNER
ORIFICE
WARNING
Failure to follow this warning could result in personal
injury or death.
Do not use gas piping as an electrical ground. Unit cabi-
net must have an uninterrupted, unbroken electrical ground
to minimize the possibility of personal injury if an electrical
fault should occur. This ground may consist of electrical
wire connected to unit ground lug in control compartment,
or conduit approved for electrical ground when installed in
accordance with NEC (National Electrical Code); ANSI/
NFPA 70, latest edition (in Canada, Canadian Electrical
Code CSA [Canadian Standards Association] C22.1), and
local electrical codes.
DRAIN
(FACTORY-IN
S TALLED)
PLUG
CONDEN S ATE PAN ( S IDE VIEW)
S TANDARD
S IDE DRAIN
ALTERNATE
BOTTOM DRAIN
MINIMUM PITCH
1
” (25mm) PER
10 ’ ( 3 m) OF LINE
BA S E RAIL
OPEN
VENT
TO ROOF
DRAIN
DRAIN PLUG
ROOF
CURB
S EE NOTE
2 in.
(51) MIN