Ducting; Supply Air Adjustments (4 Speed Motors); Table 1: Blower Speed Adjustments, 4 Speed Motor - Carrier OBM112 Series Installation Instructions Manual

g. Halogen type refrigerants;
h. Cleaning solvents (such as perchloroethylene);
i. Printing inks, paint removers, varnishes, etc. ;
j. Hydrochloric acid;
k. Solvent based glue;
l. Antistatic fabric softeners for clothes dryers;
m. Acid based masonry cleaning materials.
2.8.2 Burner with Outdoor Combustion Air Kit
Certain burners are designed to function with combustion air
taken directly from the outside. Follow the instructions provided
with the burner, the fresh-air supply kit or the side-wall venting
kit.
2.9 OIL TANK
WARNING
Fire and explosion hazard.
Use only approved heating type oil in this furnace.
DO NOT USE waste oil, used motor oil, gasoline or
kerosene.
Use of these will result in death, bodily injury and/or
property damage.
CAUTION
When a 0.75 USGPH or smaller nozzle is used, a 10 micron or
finer filter, must be installed on the oil supply line to the
furnace inside the building where the unit is located.
This is a requirement in order for the heat exchanger warranty
to remain in force.
Check your local codes for the installation of the oil tank and
accessories.
At the beginning of each heating season or once a year, check
the complete oil distribution system for leaks.
Ensure that the tank is full of clean oil. Use No.1 or No.2
Heating Oil (ASTM D396 U.S.) or in Canada, use No.1 or No.2
Furnace Oil.
A manual shut-off valve and an oil filter shall be installed in
sequence from tank to burner. Be sure that the oil line is clean
before connecting to the burner. The oil line should be
protected to eliminate any possible damage. Installations
where the oil tank is below the burner level must employ a two-
pipe fuel supply system with an appropriate fuel pump. A rise
of 2.4 m (8') and more requires a two stage pump and a rise
greater than 4.9 m (16') an auxiliary pump.
Follow the pump instructions to determine the size of pipe
needed in relation to the rise or to the horizontal distance.
2.10

DUCTING

WARNING
Poisonous carbon monoxide gas hazard.
DO NOT draw return air from inside a closet or utility
room. Return air MUST be sealed to the furnace
casing.
Failure to properly seal ducts can result in death,
bodily injury and/or property damage.
The ducting must be designed and installed according to
approved methods, local and national codes as well as
good trade practices.
When ducting supplies air to a space other than where the
furnace is located, the return air must be sealed and also
be directed to the space other than where the furnace is
located.
2.10.1 Air filter
A properly sized air filter must be installed on the return air
side of the unit. Refer to the Technical Specifications,
Table 6 for the correct dimensions. Also refer to Section
2.2 and the instructions supplied with the filter.
2.11 SUPPLY AIR ADJUSTMENTS
(4 SPEED MOTORS)
On units equipped with 4-speed blower motors, the supply
air must be adjusted based on heating/air conditioning
output and the static pressure of the duct system. For the
desired air flow refer to the following table as well as the
air flow table 7 based on static pressure in the Technical
Specifications section of this manual.

Table 1: Blower speed adjustments, 4 speed motor

FURNACE HEATING OR A/C
APPLICATION OUTPUT
0.68 USGPH
HEATING
0.80 USGPH
2.0 TONS
2.5 TONS
A/C
3.0 TONS
3.5 TONS
To effect the adjustment, the RED (for heating) and BLUE
(for cooling and heat pump) wires can be changed on the
motor. Also, refer to the position of the wires on the
electronic board of the unit and consult the wiring
diagrams. If the heating and air conditioning speeds are
the same, the RED wire must be moved to "UNUSED
LEADS" on the electronic board and the jumper provided
with the BLUE wire must be used between the "HEAT"
and "COOL" terminals.
The blower start/stop delays can be adjusted by
positioning the DIP switches on the electronic board as
shown in the following figures. The recommended blower
ON delay is 60 seconds and blower OFF delay 2 minutes:
8
RECOMMENDED
BLOWER SPEED
MED-LOW
MED-HIGH
LOW
MED-LOW
MED-HIGH
HIGH