Water Furnace SAH Series Installation Manual page 27

SAH 5 Speed ECM Blower Performance Data Option A cont.
5-Speed ECM Constant Torque Motors
The 5-Speed ECM is a 'Constant Torque' ECM motor and
delivers air flow similar to a PSC but operates as efficiently
as an ECM Motor. Because it's an ECM Motor, the 5-Speed
ECM can ramp slowly up to down like the ECM motor. There
are 5 possible speed taps available on the 5-Speed ECM
motor with #1 being the lowest airflow and #5 being the
highest airflow. These speed selections are preset at the
time of manufacture and are easily changed in the field if
necessary.
If more than one tap are energized at the same time, built
in logic gives precedence to the highest tap number and
allows air flow to change with G, Y1, Y2 and W signals. Each
of those 5 speeds has a specific 'Torque' value programmed
into the motor for each speed selection. As static pressure
increases, airflow decreases resulting in less torque on the
rotor. The motor responds only to changes in torque and
adjusts its speed accordingly.
The 5-Speed ECM motor is powered by line voltage but the
motor speed is energized by 24 VAC.
5-Speed ECM Benefits:
• High Efficiency
• Soft Start
• 5 speeds with up to 4 speeds on-line
• Built-in logic allows air flow to change with G, Y1, Y2
and W signals
• Super efficient low airflow continuous blower setting.
SAH AIR HANDLER INSTALLATION MANUAL
Setting Blower Speed - 5-Speed ECM
5-Speed ECM blower motors have five (5) speeds of which
three (3) are selectable on single speed and four (4) are
selectable on dual capacity.
Caution: Disconnect all power before
performing this operation.
5-Speed ECM Motor Connections -
Single Speed Splits
C - Black
L - Orange
G - Green
G - Blue
Y1 - Red
5-Speed ECM Motor Connections -
Dual Capacity Splits
C - Black
L - Orange
G - Green
G - Blue
Y1 - Red
27
High Voltage
Connections
3/16 in.
C
G N
L
N - Brown
AUX - Gray
1 2 3 4 5
Low Voltage
Connections 1/4 in.
High Voltage
Connections
3/16 in.
C
G N
L
N - Brown
AUX - Gray
3 4 5
1 2
Y2 - Tan
Low Voltage
Connections 1/4 in.