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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connections and will display Status Code 16, System Communication
Fault, on amber STATUS LED. No further fan coil troubleshooting
information will be available at Observer wall control until
communications are re-established.
If COMM LED does not light within proper time period and status code
is not displayed:
1. Check system transformer high and low voltage to be sure the
system is powered.
2. Check fuse on fan coil control to be sure it is not blown. If fuse is
open, check system wiring before replacing it to be sure a short
does not cause a failure of replacement fuse.
If COMM LED does not light within proper time period and status code
is displayed:
Check system wiring to be sure Observer wall control is powered and
connections are made DX+ to DX+, DX- to DX-, etc. and wiring is not
shorted. Mis-wiring or shorting of the DX+, DX-, C, R communications
wiring will not allow successful communications.
NOTE: Shorting or mis-wiring low voltage system wiring will not cause
damage to fan coil control or Observer wall control but may cause low
voltage fuse to open.
ECM Motor Troubleshooting
The ECM motor used in this product consists of two parts: the control
module and the motor winding section. Do not assume motor or module
is defective if it will not start. Use the designed-in LED information aids
and follow troubleshooting steps described below before replacing
motor control module or entire motor. Motor control module is available
as a replacement part.
A12231
Fig. 8 – FCM4 ECM 3.0 Motor
VERIFY MOTOR WINDING SECTION:
Before proceeding to replace a motor control module:
1. Check motor winding section to be sure it is functional.
2. Remove motor control module section and unplug winding plug.
Motor shaft should turn freely, resistance between any two motor
leads should be similar and resistance between any motor lead and
unpainted motor end should exceed 100,000 ohms.
3. Failing any of these tests, entire ECM motor must be replaced.
4. Passing all of the tests, motor control module alone can be replaced.
MOTOR TURNS SLOWLY:
1. Low static pressure loading of blower while access panel is
removed will cause blower to run slowly, particularly at low airflow
requests. This is normal, do not assume a fault exists.
2. Recheck airflow using Observer wall control service screens with
access panel in place.
NOTE: Blower motor faults will not cause a lockout of blower
operation. Fan coil control will attempt to run the blower motor as long
as the Observer wall control maintains a demand for airflow. Fan coil
control will not operate electric heaters while a fault condition exists.
The fan coil control communicates with the motor at least once every
five seconds, even when the motor is idle. If, during operation, the fan
coil control does not communicate with the motor for more than 25
seconds, the motor will shut itself down and wait for communications to
be reestablished.
Using Motor LED in Troubleshooting
The MOTOR LED is connected to the blower motor communication line
and works with the fan coil control microprocessor and the STATUS
LED to provide fan coil operation and troubleshooting information.
When the motor is commanded to operate, the MOTOR LED will be
turned on and will flash each time instructions are sent to the motor.
WARNING
!
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury or death or
possible equipment damage.
After disconnecting power from the ECM motor, wait at least five
minutes before removing the control section. Internal capacitors require
time to discharge. Minor injury from electrical shock may result from
early contact with live metal parts.
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