Check Power To Motor; Regal-Beloit — Blower B3 Harness - Lennox CBX40UHV Series Installation And Service Procedure

The DC filter capacitors inside the controller are connected
electrically to the motor supply wires. The capacitors take
approximately 5 minutes to discharge when the disconnect
is opened. For this reason it is necessary to wait at least 5
minutes after turning off power to the unit before
attempting to service motor.
DANGER
Disconnect power from unit and wait
at least five minutes to allow capaci­
tors to discharge before attempting to
service motor. Failure to wait may
cause personal injury or death.
Indoor Blower Motor (B3) Control Troubleshooting
(Regal-Beloit)
To verify motor operation see steps below and figure 15.
NOTE: If the communication channel is disrupted (loss of
communication and and 24VAC) to the air handler control,
the motor will continue to operate at its current mode. This
means, if the motor is currently in idle, it will stay in idle
mode; if it is currently running, it will stay running at the
current operating point.

Check Power to Motor

1. Remove J48 (5-pin power plug) from P48 on the motor.
2. With the power on at the air handler, use a test meter to
verify 240V between pins 4 and 5 on J48.
3. Reconnect J48 to P48 on the motor.
APPLY TEST SIGNAL FOR MOTOR OPERATION
1. Remove J49 (4-pin low voltage connector) from P49 on
the motor.
2. Using test jumpers, apply 24V to pins 3 and 4 on P49 on
the motor.
Note: Do not apply 24V to pins 2 and 4 on P49. Doing so
will cause permanent damage to the motor.
3. Motor should run at 75%.
CBX40UHV
4. Test is complete. Remove jumpers and reconnect
plugs.
Another option is to use the TECMate PRO with the 16 to
4 pin adaptor. The use of the TECMate PRO isolates the
motor from the integrated control. Follow the instructions
provided with the kit. If the motor runs do not replace.
P48 5 PIN
J48 5 Pin
J49 4 Pin
Figure 15. Regal-Beloit — Blower B3 Harness
Page 21
P49 4 PIN
MOTOR with INTEGRATED
CONTROLLER
J48 5 Pin Line Voltage Connector
J49 4 Pin Control Connector
Connectors