Outside air temperature sensor
For 100% return air units (with NO fresh air), it is
required to have an outside air temperature (OAT)
sensor.
Field install the factory supplied kit that is shipped
loose, secured to the draw-through filter rack in the
filter section of the unit.
1. Locate the OAT sensor on the right-side
column of the return air section.
2. Drill a 3/8 in. hole at the specified dimensions
according to Figure 33.
3. Install the factory suppled grommets on both
sides of the drilled hole.
4. Install the OAT sensor to the column using
the two factory supplied clamps and two self-
tapping screws.
5. Make a small hole through the insulation to
pass the sensor wires through the grommets.
6. Connect the sensor wires to the OAT sensor.
7. Caulk around the wires and the grommets.
Figure 33: Installing the OAT sensor
Gas piping
The unit can have optional factory installed staged
or modulating gas heating sections. When optional
gas heat is ordered, natural gas is the standard
offering. Propane can be ordered as an option.
The installing contractor is responsible for the
proper sizing of the inlet gas piping. Proper sizing
depends on the cubic feet per hour of gas flow
required, specific gravity of the gas, and the length
of piping run.
The latest edition of the National Fuel Gas Code
Z223.1 should be followed in all cases unless
superseded by local codes. Refer to Table 52.
The maximum gas pressure allowed at the unit
connection is 0.5 psig or 13.5 iwg.
WARNING
If the information in this manual is not followed
exactly, a fire or explosion can result and cause
property damage, personal injury, or loss of life.
Do not store or use gasoline or other flammable
vapors and liquids in the vicinity of this or any
other appliance. WHAT TO DO IF YOU SMELL
GAS:Do not try to light any appliance. Do not touch
any electrical switch, and do not use any phone in
your building. Immediately call your gas supplier
from a neighbor’s phone. Follow the gas supplier’s
instructions.If you cannot reach your gas supplier, call
the fire department. Installation and service must be
performed by a qualified installer, service agency, or
the gas supplier.
WARNING
Disconnect gas piping from unit when leak testing at
pressures greater than 0.5 psig or 13.5 iwg. Pressures
greater than 0.5 psig or 13.5 iwg will cause gas valve
damage resulting in a hazardous condition. If the gas
valve is subjected to pressure greater than 0.5 psig or
13.5 iwg, it must be replaced.
Tempmaster
®
Omni™ Premier 25 Ton to 80 Ton Rooftop Units Installation and Maintenance Guide
76
Tempmaster
