Constant Torque Motors (Ecm) - Bosch SM024 Installation, Operation And Maintenance Manual

36 | ECM INTERFACE BOARD
3. To the left of the red and green status LED's is
a row of 1/4" male quick connects. These are
used to pass thermostat inputs on to the rest
of the control circuit. Remember to always turn
off unit power at the circuit breaker before
attaching or disconnecting any wiring from
these connections to avoid accidental short
circuits that can damage unit control
components.
Dehumidification indicator LED (Figure #104, item
[4]) will energize when dehumidification call is
present.
Figure # 104

Constant Torque Motors (ECM)

For installations where the efficiency of an
electronically commutated brushless DC motor
(ECM) motor is required, but the features of a
constant airflow motor are not required, the LM
series comes standard with the constant torque
ECM motor option. These motors feature up to
90% thermal efficiency combined with a flatter fan
curve than a PSC motor and simple operation.
These motors are provided with 5 speed taps to
allow for a wide range of air flow and external
static options.
To change a speed tap follow the instructions
below:
1. Disconnect power to the heat pump.
2. Remove the blower access panel.
3. Remove the speed tap wire from the terminal it
is currently connected to and connect it to the
terminal desired.
Refer to the constant torque motor performance
tables for heat pump blower performance with the
constant torque motor option. (Pg#62)
6 720 220 406 (2015/02) Subject to change without prior notice
SM Series Heat Pump
SM Series Heat Pump