Self-Diagnosis And Troubleshooting - Mitsubishi Electric PRH-P8MYA Technical & Service Manual

[9] Self-diagnosis and troubleshooting

<Abnormality detected at power on>
Abnormal- Meaning of abnormality display and
ity display abnormality troubleshooting
None
Indoor/outdoor connection erro-
neous wiring
1. Outdoor-side controller board
automatically recognizes the
number of connected indoor-side
unit. However, when the number of
connected indoor unit cannot be
EA
set due to erroneous indoor/
outdoor connection, erroneous
wiring, etc. even after 4 minutes
have elapsed since the power
was turned on, an abnormality
is recognized.
Indoor/outdoor connection erro-
neous wiring
Outdoor-side controller board
automatically sets the unit No. of
the indoor unit. However, when
the unit No. of the indoor-side unit
Eb
cannot be set due to indoor/outdoor
connection erroneous wiring even
after 4 minutes has elapsed since
the power was turned on, an
abnormality is recognized.
Start-up time over
When start-up processing does not
end even through 4 minutes has
EC
elapsed since the power was turned
on, an abnormality is recognized.
F1 Reverse phase detected
Cause
(1) Voltage not applied to unit terminal
block TB1.
a. Power supply circuit breaker not
closed.
b. Power supply terminals connection
faulty, or disconnected.
c. Missing phase
(2) No electricity at outdoor-side controller
board power supply connector.
a. Power supply connector contact
faulty.
b. Terminal CN20 on outdoor-side
controller board disconnected.
(3) Outdoor-side controller board faulty.
a. Blown fuse on outdoor-side
controller board.
b. Part faulty.
(4) Transformer faulty
(1) Indoor/outdoor connection wire con-
tact faulty.
(2) Outdoor-side controller board send/
receive circuit faulty.
(3) Indoor-side controller board send/
receive circuit faulty.
(4) Noise has entered on power supply
or indoor-side/outdoor-side
controller board connection wire.
(1) Indoor/outdoor connection wire con-
tact faulty.
(2) Outdoor-side controller board send/
receive circuit faulty.
(3) Indoor-side controller board send/
receive circuit faulty.
(4) Noise has entered on power supply
or indoor-side/outdoor-side
controller board connection wire.
(1) Indoor-side/outdoor-side controller
board connection wire contact faulty.
(2) Noise has entered on power supply
or indoor-side/outdoor-side
controller board connection wire.
(1)
Power supply reverse phase
connection.
(2) Power supply missing phase.
- 60 -
Judgment method and remedy
(1)a. Check power supply circuit breaker
b. Check power supply terminal block
connections.
c. Check power supply terminal block
connections.
(2)a. Check power supply connector board
connections.
(3)a. Replace fuse.
b. Replace controller board.
(However, when cannot be repaired
even through the check above was
carried out.)
(4) Replace transformer
(1) Check if indoor/outdoor connection
wire disconnected or loose. Also
check polarity.
(2) Check by turning power off and on.
If abnormality is displayed again, re-
place outdoor-side controller board or
indoor-side controller board.
* LED3 of the indoor-side controller
board flashes when communication
is being performed.
(1) Check power supply terminal block
connections.
(2) Replace outdoor-side controller board
(However, when cannot be repaired
even though check above was carried
out.)