FCM4, FEV, FEM4, FJM, FMA4, FSA4, FSM4, FSU4, FVM4, FXM4, REM4, WAH, WAM, WAP, WAX, WBHL: Service and Maintenance Instructions
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
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from laboratory testing If any two characteristics are known, the third is
defined.
Requested airflow is known from Easy Select Board configuration and
thermostat signals. Torque is known because it is directly related to
stator current, which is measured by motor control. Speed is measured
by counting back EMF pulses from stator windings. This information is
entered into an expression that calculates torque from speed and airflow
numbers. If calculation does not match stored blower characteristics,
torque is adjusted until agreement is reached. This calculation and
adjustment is performed every 0.8 seconds while motor is in operation.
There is no direct measure of static pressure, but unit does react to a
change in static to maintain constant airflow. A change in pressure will
result in a change in stator speed and torque. The motor will begin to
adjust on the next sampling, calculate new desired speed and torque, and
adjust as necessary.
INTEGRATED CONTROLS AND MOTOR ECM 5.0
An ECM 5.0 is fed high voltage AC power through the 5-pin connector
(Fig. 3). The AC power is then internally rectified to DC by a diode
module. After rectification, DC signal is electronically communicated
and fed in sequential order to three stator windings. The frequency of
these commutation pulses determines motor speed. The rotor is
permanently magnetized.
An ECM 5.0 is powered with high voltage at all times. The motor will
not run with high voltage alone. Low voltage must be applied to control
plug to run motor.
ECM 5.0 Control Power
The ECM 5.0 control power is supplied from R circuit through printed
circuit runs to motor control Connector (Pin 8), through motor control
harness to motor. The C side of low-voltage control power circuit is
connected by printed circuit runs to motor Connector (Pins 9, 10, and 11)
then through motor control harness to motor.
Low-Voltage Circuit Fusing and Reference
The low-voltage circuit is fused by a board-mounted 5-amp
automotive-type fuse placed in series with transformer SEC2 and R
circuit. The C circuit of transformer is referenced to chassis ground
through a printed circuit run at SEC1 connected to metal standoff
marked.
NOTE: The PCB must be mounted with two screws and motor ground
lead secured to blower housing or erratic motor operation can result.
Transformer, Motor, and Electric Heater Power Connection
Transformer high voltage supplied from electric heater package or high
voltage leads through 12-pin heater connector plug2/recp2. The ECM
5.0 power connections are made at the transformer primary terminals.
The transformer secondary connections are made at SEC1 and SEC2
connectors.
PCB LAYOUT AND DESCRIPTION
NOTE: Layout of actual PCB is depicted in Fig. 5.
The Easy Select Board is the interface between the ECM motor and
other system components. The board offers choices of electric heater
size, outdoor unit size and type, comfort or efficiency settings, on and off
delay profiles, and continuous fan speed. The installer should select the
correct size of components that are being installed in each installation. If
no selections are made, the factory default settings are for the largest
heater, largest outdoor unit, AC system type, nominal airflow adjust, and
0/90 time delay.
NOTE: Outdoor unit model should have an AHRI rating with the
variable speed fan coil. Some outdoor unit models will not work
properly with this fan coil.
Power for system is supplied from a 230VAC, 60-Hz line. Class 2
voltage (24VAC nom.), used for thermostat connections, is derived from
transformer located in close proximity to PCB. The 24VAC secondary
circuit includes 5A automotive-type fuse in SEC2 circuit.
Connection to heater panel is made through 12-pin connector PL-1.
Connections to thermostat are made at screw terminals. Twenty-one pin
terminals comprise field select taps for motor.
Fuse Data: 5A automotive-type ATC/ATO (tan) at 32VAC, 200 percent
current opening time of five seconds maximum.
Electrical Connections
Twenty-one 0.110-in pin terminals are used to provide programming
selections for operating modes of ECM 5.0. The 6 selection modes are
listed below. For additional information, refer to Easy Select
Configuration Taps section.
• AUX Heat Range—(Violet Wire)
• AC/HP Size—(Blue Wire) Type—(Orange Wire)
• AC/HP CFM Adjust—(Black Wire)
• AC/HP Time Delay—(Grey Wire)
• Continuous Fan—(Yellow Wire)
SEQUENCE OF OPERATION
Continuous Fan Mode
The thermostat closes circuit R to G. The unit delivers the airflow
selected for fan only operation.
Cooling Mode—Single Speed or Two-Speed High
Thermostat closes circuits R to G, R to Y/Y2 and R to O (heat pump
only). A circuit R to Y1 is required for two-speed high operation.
Airflow delivered the airflow selected by AC/HP SIZE selection and
CFM ADJUST selection.
Cooling Mode—Two-Speed Low
Thermostat closes R to G and R to Y1 and R to O (heat pump only). Unit
delivers two-speed low airflow for AC/HP SIZE and CFM ADJUST
selected.
Cooling + Dehumidify Mode
J1 jumper must be pulled from Easy Select Board. Control closes R to G,
R to Y/Y2, and R to O (heat pump only) and open R to DH.
Dehumidification is active when 24VAC is removed from DH terminal.
Unit delivers 20 percent less airflow.
Super Dehumidify Mode
This mode is only activated when the control closes R to Y/Y2, R to O
(heat pump only) and opens R to DH and R to G. This signals the fan coil
to run at minimum airflow for maximum humidity removal. The control
will cycle the equipment 10 minutes on and 10 minutes off until
satisfied.
Table 2 – Motor and Modules
Model Size Motor Type Current Blower Motor P/N
Required Control Module
Replacement Kit Number
FVM4X2400 (Series B) ECM 5.0 1185246 1185326
FVM4X3600 (Series B) ECM 5.0 1185247 1185327
FVM4X4800 (Series B) ECM 5.0 1185248 1185328
FVM4X6000 (Series B) ECM 5.0 1185249 1185329
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