•
Use wrought iron or steel pipe for all gas lines.
Thread sealing compounds should be used
sparingly on male threads only.
•
All piping should be cleaned of dirt and scale
by hammering on the outside of the pipe and
blowing out loose particles.
•
Before initial start-up, all air should be purged
out of the gas supply line piping.
•
The gas supply should be a separate line and
installed in accordance with all safety codes as
prescribed under limitations listed previously
in this section.
•
After completion of gas connections, open the
main shut-off valve allowing gas into the unit.
All factory piping should be checked for leaks
using a soap and water solution.
•
An 1/8 in. NPT plugged tapping should be
installed immediately upstream of the gas
supply connection to the furnace.
•
The hollow grommet that is shipped as
a loose-piece item with kits should be
assembled with the fuel pipe for bottom
penetration option as shown in Figure 35. For
the side penetration option, keep the existing
grommet on the drain pan as is.
•
The hollow grommet should properly fit
between the drain pan hole and fuel pipe
outside diameter.
•
Apply proper sealant across the grommets to
seal the gap across its internal and external
diameter.
Figure 35: The hollow grommet
Component
Description
A
Drain pan
B
Hollow grommet
Component
Description
C
Bottom intake fuel
supply kit
Flue gas chimney installation
•
On units that have optional staged or
modulating gas heat, field installation of a flue
gas chimney is required.
•
The flue gas chimney is shipped loose in the
return air section of the unit.
•
Carefully remove the flue gas chimney
assembly from the return air section and
install it over the inducer motor outlets as
shown in Figure 36.
•
Install up to three diverter angles with the flue
gas chimney.
•
Number of diverter angles will vary based on
the gas heat capacity (low heat = 1, medium
heat = 2, high heat = 3).
Figure 36: Flue gas chimney assembly
Hydronic piping
The unit can have an optional factory installed hot
water coil or steam coil.
Hot water coil
•
The factory installed hot water coil is located
in the discharge air section of the unit.
Tempmaster
®
Omni™ Premier 25 Ton to 80 Ton Rooftop Units Installation and Maintenance Guide
78
Tempmaster
