Carrier RAV-SP180UT-UL Service Manual page 85

[P12 error]
Turn off the power.
Is there no connection error or
disconnection on connectors CN333
and CN334 of indoor unit P.C. board?
NO
Remove connectors CN333
and CN334 of indoor unit P.C. board.
Does the fan rotate without trouble
when handling the fan with hands?
YES
Are resistance values between
phases at fan motor connector
CN333 motor side of
indoor P.C. board correct?
Correct
Is resistance value of
fan motor connector CN334 motor side
of indoor P.C. board correct?
Correct
Is output of
indoor fan motor position
detection signal correct?
YES
YES
NO
Incorrect
∗1
∗1
• Are not coil windings between
between (White lead) and
between (Black lead) and
→ The resistance should be the resistance value below.
SP180, SP240
SP300, SP360, SP420 → 4-Way: Approx. 27 to 40Ω,
• Is not grounded between cabinet and
Incorrect
∗2
∗2
Resistance value confirmation of the fan motor position detection circuit
Is not status between (Yellow lead) and
→ The resistance should be approx. 5k to 20kΩ.
NO
∗3
∗3
Confirmation of the fan motor position detection signal
• Using a voltage tester, measure voltage between CN334
under condition that CN333 and CN334 are mounted and the power supply is turned on.
→ When rotating the fan slowly with hands, the pin voltage should shake between 0 and 5V.
• Between and : 5V
Correct connection
of connector.
Replace indoor fan motor.
(Red lead) and (White lead),
(Black lead),
(Red lead) opened or shorted?
→ Approx. 70 to 100Ω
Under Ceiling: Approx. 35 to 50Ω
. → It should be 10MΩ or more.
, ,
(Pink lead) opened or shorted?
– 85 –
CN333
CN334
Replace indoor fan motor.
Replace indoor fan motor.
Replace indoor fan motor.
and on the indoor P.C. board
Check indoor P.C. board.
Defect → Replace