Nordyne O4HD-091A-14-FA-DV Installation, Operation And Maintenance Manual page 10

temperature h asdropped andthe limitcontrol h asreset,
thefanwilloperate untilthefanofftimeis achieved. The
oil burnerwill thenresumeoperation andcontinue until
thethermostat is satisfied. R estore thethermostat setting
toa comfortable temperature.
NOTE: IF THE FURNACE IS TO BE SHUT DOWN
FOR AN EXTENDED PERIOD OF TIME, CLOSE
THE OIL SUPPLY VALVE TO THE BURNER.
I'ACAUTION I
DO NOT ATTEMPT TO START THE BURNER
WHEN EXCESS OIL HAS ACCUMULATED,
WHEN THE FURNACE IS FULL OF VAPOUR, OR
WHEN THE COMBUSTION CHAMBER IS VERY
HOT. NEVER BURN GARBAGE OR PAPER IN
THE FURNACE, AND NEVER LEAVE PAPER OR
RAGS AROUND THE UNIT.
22. ECM BLOWER MOTOR OPERATION
(O4HD-091A-V-FA)
Setting Blower "ON" and "OFF" Timings
Blower on/off time delays are handled by ECM
motor programming. Features of this ECM variable
speed motor are that it will deliver a constant airflow
within a wide range of external static pressures, and
also includes:
Soft Start: This ECM variable speed motor will
slowly ramp up to the required operating speed.
This feature in the heating cycle allows the heat
exchanger to reach operating temperature before
the set heat speed, which minimizes noise and
increases comfort.
Soft Stop: At the end of the heating cycle, the ECM
variable speed motor will slowly ramp down. This
feature allows for increased energy efficiency and
reduced noise levels.
Dehumidification: A dehumidification feature has
been programmed into the variable speed motor. At
the start of each cooling cycle, the variable speed
motor will run at 82% of the rated airflow for 7.5
minutes. After 7.5 minutes has elapsed, the motor
will increase to 100% of the rated airflow. This
profile is used to provide dehumidification and
improve system efficiency.
Continuous Fan Operation : When the thermostat
continuous fan (G) switch is on without a call for
heating or cooling, the indoor fan is immediately
energized up to 50% of the cooling speed. This
feature allows continuous circulation of air between
calls for heating or cooling.
If a call for heat (W) or cool (Y) occurs during
continuous fan, the blower will remain energized
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