Fan Motor Options
14.3 Constant Airflow Motors (ECM)
NOTICE
The 460-V heat pump units that are equipped with the
Constant Airflow Motor option require power-supply wiring
that includes a properly-sized neutral wire in addition to the
three high-voltage wires and the ground wire. These units
employ a 265-V motor that requires power from one phase of
the 460-V supply and the neutral wire.
For installations where constant air delivery is critical or where
external static pressure drop can vary greatly (such as with
high-MERV value filters) the CL series is offered with a constant
air flow EC
M motor option. This option provides ECM motor
efficiency combined with a constant air delivery across a wide
range of external static pressures. These motors dynamically
adjust their power output to precisely match the desired air flow
on a pre-programmed fan curve.
Additionally these motors feature:
• A low-CFM ventilation feature that circulates air at 70% of full
load when “fan only” is called.
• A passive dehumidification mode that reduces air flow during
a cooling call when dehumidification is also required—this
reduces the sensible heat ratio of the cooling coil and extends
cooling run time to more effectively dehumidify. (
Refer to
the ECM Interface Board section on page #23.)
• Three-speed settings per model. Units are factory set to
“NORM” but can be field adjusted to “+” to increase CFM by
15% or to “-” to reduce CFM by 15%. (
Refer to the ECM
Interface Board section on page #23.)
• A “TEST” mode that operates the motor at a 70% torque
setting. This setting can be used to diagnose programming
problems in the motor itself. (
Refer to the ECM Interface
Board section on page #23.)
• A CFM indicator light that provides a blink for each 100 CFM
of air delivered. (Note that this blink code is approximate and
should not replace testing and balancing.)
Refer to the constant air flow motor performance tables below
for heat pump blower performance with the constant air flow
motor option.
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CL Series Heat Pumps — 8733838716 (2024/05)
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