Service Manual

SERVICE AND MAINTENANCE FAN COILS
496 08 8001 02 13
Specifications subject to change without notice.
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.
C. 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.
Figure 8 − FCM4 ECM 3.0 Motor
A12231
VERIFY MOTOR WINDING SECTION:
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.
!
WARNING
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.
D. 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.
When the motor is commanded to stop, the MOTOR LED will
be turned off.
If the MOTOR LED is lit, flashing and the motor is running or if
the MOTOR LED is off and the motor is stopped, operation is
normal and no motor fault exists.
If the MOTOR LED is lit, flashing and the motor does not run,
or if the MOTOR LED is off and the motor is running, check the
STATUS LED for the Status Code. Refer to the
troubleshooting instructions for the indicated Status Code in
Section E, Fan Coil Troubleshooting.
E. Fan Coil Troubleshooting
Fan coil faults indicated by flashing codes on the amber
system STATUS LED can be resolved using troubleshooting
information provided below. Codes are listed in order of their