Boyertown Regal Oil Furnace Nrg Max - Manual (Page 10)

10
ECM MOTOR OPERATING MODES
Introduction
The ECM 5.0 motor is a variable speed, high effiency motor which has the ability to produce constant
air flow within a system, independent of static pressure. It achieves constant air flow by adjusting
speed and torque to account for changes in system static pressure. The GE ECM uses a proprietary
mathmatical algorithim to model air moving systems driven by forward curved blower wheels.
Operating Modes
The ECM motor is controlled by 24VAC thermostat signals to determine which mode of operation the
blower is to run. Air flow rates in the different modes are controled by the setting of the DIP
switches.
Standby Mode:
The thermostat inputs are being continuously monitored . The motor will respond to the 24
volt AC input signal from the thermostat.
Fan Mode:
When a call for fan operation is received from the thermostat (“G” line is energized) the
blower will operate at a reduced speed as determined by the position of the cooling DIP
switches as set for the airconditioning speed. See air flow tables for DIP switch and air flows.
If a call for cooling or for heating is energized along with the call for fan only the unit will run
at the respective air flow for heating or cooling. Electronic air cleaner terminal “EAC” is
energized
Cooling Mode:
When a call for cooliong is received from the thermostat (“Y” line is energized) the motor will
operate at the cooling speed and profile as adjusted by the cooling DIP switches. Cooling air
flow is profiled to ramp the air flow up to the full cooling air flow to allow for maximum
dehumidification. Electronic air cleaner terminal “EAC” is energized
Heat Mode:
When a call for heat is received from the thermostat (“W” line is energized) the motor will
operate through the heating cycle at the air flow as adjusted by the heating DIP switch. When
a call for heat is initiated the blower will turn on after a 30 second delay to ensure warm
plenum temperatures as the furnace heats up. The blower then runs at a reduced rate before
increasing its speed to the full air flow requireements.
When the call for heat is satisfied the blower will continue to operate at a reduced rate for a
period of 3 minutes to remove all of the usable heat from the furnace while still maintaining
the plenum temperatures at a comfortable level. Electronic air cleaner terminal “EAC” and
humidifer terminal “H” are energized
ECM Motor Air Flow Selection
Air flow settings for both heating and cooling are made by setting the heat and the cool airflow DIP
switches to the proper location. Ensure the furnace power supply is off before adjusting blower
speeds. Do not adjust the heating air flow below the firing rate of the furnace. The air flows for
heating are designed to give a 70
o F temperature rise.