Daikin ComfortNet DX7TC Service Instructions Manual page 109

TROUBLESHOOTING
Troubleshooting
Error Code:
B2 - Blower motor operating in
power, temp or speed limiting
conditions
B3 - Circulating blower motor is
operating in a power, temperature,
or speed limiting condition
B4 - Blower motor- Current trip
(or) lost rotor
B5 - Circulator blower motor fails
to start 10 consecutive times
B6 - Circulator blower motor shuts
down for over or under voltage
condition. Circulator blower motor
shuts down due to over
temperature condition on power
module
B9 - Low indoor airflow (with
electric heat mode)
Applicable Models:
Indoor equipment
Method of Error Detection:
B2 - According to the control
status flags of the motor
B3 - Air handler operates at
reduced performance. Airflow
delivered is less than expected
B4 - According to the control
status flags of the motor
B5 - No air handler operation
B6 - No air handler operation
B9 - Number of revolutions of the
blower motor
Error Decision Conditions:
B2 - When the motor sets Control
Status Flags (bit3, bit4 or bit9) (*).
bit3=Power limit
bit4=Temp limit
bit9=Over temp
B3 - When the motor sets Control
Status Flags (bit3, bit4 or bit9) (*).
bit3=Power limit
bit4=Temp limit
bit9=Over temp
B4 - When the motor sets Control
Status Flags (bit5=1 or bit6=1) (*).
bit5=Lost Rotor trip
bit6=Current trip
B5 - When the motor is locked up
and the demand for operation has
been presented 10 times with no
operation
B6 - High/low voltage is detected
in the controller.
B9 - When EH demand is active
and the above
conditions.
• When "50rpm<Feedback
rpm"<"Minrpm(150rpm) " is
detected for 10 times consecutive-
ly
Or
• When feedback from motor's rpm
is 50rpm > and Min rpm (150rpm)
and it happens 360 times).
(When checked rpm reaches 720
times,)
Board flashes
B2-B6 or B9
Does the air
No
handler have the
correct blower
motor?
Yes
Does the air
No
handler have the
correct shared
data?
Yes
Does the air handler
have blocked filters, No
restrictive ductwork,
or undersized
ductwork?
Yes
Is the air handler
operating in a high
No
ambient condition
outside of the
temperature range
specified?
Yes
Check primary voltage
to blower motor. Is the
power supply voltage No
between 104 and 142
vAC (115vAC + 10%)?
(Typically 115 –
127vAC?
Yes
ERROR CODE - B2-B6, B9
Error Code - B2-B6, B9
Verify correct motor horsepower.
Replace if necessary
Verify shared data set is correct
for specific model. Repopulate
shared data if required
Clean filters, remove
obstructions, verify registers are
fully open and RA grilles are not
blocked. Verify ductwork is
appropriately sized.
Resize/replace ductwork if
necessary.
Address high ambient condtion
if necessay
Correct power supply if out of
range
Replace motor if necessary
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