Circulating Air Blower (Ecm) - Nordyne O4HD-091A-12-FA Installation Instructions Manual

accessible area between the furnace and
furnace room entry, and be located in
such a manner to reduce the likelihood
that it would be mistaken as a light
switch or similar device.
The power requirements for all models:
120 VAC, 1 ∅, 60 Hz., 12A.
Accessories requiring 120 VAC power
sources such as electronic air cleaners
and humidifier transformers may be
powered from the EFTB (Electronic Fan
Timer Board). Do not use the direct drive
motor connections as a power source,
since there is a high risk of damaging the
accessories by exposure to high voltage
from the auto-generating windings of the
direct drive motor.
Thermostat wiring connections and air
conditioning contactor
connections are shown in the wiring
diagrams. Some micro-electronic
thermostats require additional controls
and wiring. Refer to the thermostat
manufacturer's instructions.
The thermostat should
approximately 5 feet above the floor, on
an inside wall where there is good
natural air circulation, and where the
thermostat will be exposed to average
room temperatures. Avoid
where the thermostat will be exposed to
cold drafts, heat from nearby lamps and
appliances, exposure to sunlight, heat
from inside wall stacks, etc.
Normal heat anticipator setting: 0.1 A.
For more precise adjustment, the heat
anticipator may be adjusted to the
amperage draw of the heating control
circuit as measured between the "R" and
"W" terminals of the thermostat. To
reduce the risk of damaging the heat
anticipator, do not measure
without first removing one of the two
wires first. To determine the heating
circuit amperage draw:
1. With the power off to the appliance,
disconnect one of the "R" or "W"
wires from the thermostat terminal.
2. Connect an ammeter between the
wire and the thermostat terminal to
which it was attached.
3. Restore power to the appliance and
initiate a call for heat. Note the
amperage reading when the heating
contacts are closed. (System switch
must be on " " if so equipped.
HEAT
4. Terminate the call for heat, turn
power off and re-connect
thermostat wire. If the thermostat is
serving a combination heating and
air
particular attention to polarity.
5. When the thermostat is reconnected
and re-plumbed, adjust the heat
anticipator setting to match the
observed amperage reading.
6. Restore power to the appliance.
CIRCULATING AIR BLOWER
(ECM)
All O4HD-***A-V-F furnace models are
equipped with a variable speed direct
drive blower system. The heart of the
variable speed blower is the "ECM"
motor. "ECM" stands for electronically
commutated motor. The ECM consists of
a brushless DC type motor with a
microcomputer based variable speed
drive located in the end bell. This drive
low voltage
continually monitors RPM and torque
output of the motor. This information
along with a set of blower constants
developed in a laboratory is fed into pre-
programmed
microprocessor to determine the correct
be located
motor output
constant airflow regardless of external
static pressure.
The microprocessor also stores delay
profiles developed in a laboratory to
locations
optimize the efficiency and performance
of split system air conditioners and heat
pumps. More than just on and off delays,
the variable
through intermediate airflow levels during
the preprogrammed on and off profiles.
The result is smoother more efficient
operation.
controls the rate of change of the motor's
output to create quiet, gradual starts and
stops. This kind of control is not possible
with conventional motor technology.
circuit
CONFIGURING THE BLOWER
Blower configuration should be pre-set at
the factory for the selected heat output
only however proper speed selection
should be confirmed after installation.
For cooling
dipswitches must be adjusted to match
cooling system nominal capacity. With
the variable speed blower configured
properly, the furnace will respond directly
to thermostat inputs. During normal
operation the motor will gradually change
speed in response to changes in system
variables
settings, duct static, filters etc. The
variable speed blower is configured by
setting the 7 dipswitches located on the
the control panel inside the control box
mounted on the front of the blower.
conditioning system,
algorithms in
required to maintain
speed blower "steps"
The microprocessor also
configuration, blower
such as the thermostat
7
pay
THE VARIABLE SPEED BLOWER
HAS BEEN DESIGNED TO GIVE THE
INSTALLER MAXIMUM FLEXIBILITY
TO OPTIMIZE
PERFORMANCE,
COMFORT. BECAUSE THERE ARE
SO MANY WAYS TO CONFIGURE THE
BLOWER IT IS IMPORTANT THESE
INSTRUCTIONS CAREFULLY.
CHANGES
CONFIGURATION MUST BE MADE
WITH THE POWER TO THE UNIT
TURNED OFF. THE BLOWER MAY
IGNORE CHANGES MADE WITH THE
the
POWER ON.
ECM BLOWER OPERATION
COOLING OR HEAT PUMP MODE
When the thermostat calls for cooling or
heat pump heating the circuit between R,
G and Y (O is ignored by the blower) is
completed and the blower begins a
preprogrammed on-cycle "profile". First
the blower ramps up to approximately
1/3 of the selected airflow and stays
there for 30 seconds. The blower then
ramps up to the selected airflow until the
thermostat is satisfied. A one-minute off-
cycle delay at approximately ½ of the
selected airflow is initiated when the call
from the thermostat ends.
HEATING MODE
When the thermostat calls for heating the
circuit between R and W is completed.
The furnace control board initiates the
ignition sequence. When the burner is
energized and the
completed the selected on delay a relay
is energized sending a signal to the
blower. The blower will start and run at a
very low speed. After 30 seconds, the
blower ramps up to the selected heating
airflow. The blower will operate two
minutes after the off delay of the fan
timer is satisfied.
NOTE: It is highly recommended that the
minimum on and off delay timings on the
fan timer be utilized with this blower as
premature tripping of the limit may occur
at the higher settings.
151B0801 R5 3/28/2006
SYSTEM
EFFICIENCY AND
TO BLOWER
fan timer has