Mitsubishi Electric PUZ-HA24NHA1, Service Manual

Page: 39 / 128

39
OCH750A
Abnormal point and detection method Cause Judgment and action
A0
(6600)
Address duplicate definition
This error is displayed when transmission
from the units of same address is detected.
Note: The address and attribute displayed
at remote controller indicate the con-
troller that detected abnormality.
1
There are 2 or more same
address of controller of out-
door unit, indoor unit, FRESH
MASTER, or LOSSNAY.
2
Noise has entered into trans-
mission signal and signal was
transformed.
Search the unit with same address as abnormali-
ty occurred. If the same address is found, turn off
the power supply of outdoor unit and indoor unit
and FRESH MASTER or LOSSNAY at the same
time for 2 minutes or more after the address is
corrected, and turn the power on again.
Check transmission waveform or noise on trans-
mission wire.
A2
(6602)
Hardware error of transmission
processor
Transmission processor intended to trans-
mit “0”, but “1” appeared on transmission
wire.
Note: The address and attribute display at
remote controller indicate the con-
troller that detected abnormality.
1
Error is detected if waveform is
transformed when wiring works
of transmission wire of out-
door unit, indoor unit, FRESH
MASTER or LOSSNAY are
done, or polarity is changed
with the power on and transmis-
sion data collide each other.
2
Defective transmitting receiving
circuit of transmission processor
3
Transmission data is changed
by the noise on transmission.
1
If the works of transmission wire is done
with the power on, turn off the power supply
of outdoor unit and indoor unit and FRESH
MASTER or LOSSNAY at the same time for
2 minutes or more, and turn the power on
again.
2
Check transmission waveform or noise on
transmission wire.
A3
(6603)
BUS BUSY
1. Overtime error by collision damage
Abnormal if transmitting signal is not
possible for 8-10 minutes continuously
because of collision of transmission.
2. Data could not reach transmission wire
for 8–10 minutes continuously because
of noise, etc.
Note: The address and attribute displayed
at remote controller indicate the con-
troller that detected abnormality.
1
Transmission processor could
not transmit signal because
short cycle voltage of noise
and the like have entered into
transmission wire continuously.
2
Transmission quantity has
increased and transmission is
not possible because there was
wiring mistake of terminal block
for transmission wire (TB3) and
terminal block for central con-
trol (TB7) in outdoor unit.
3
Transmission are mixed with
others and occupation rate on
transmission wire rose because
of defective repeater (a func-
tion to connector or disconnect
transmission of control and
central control system) of out-
door unit, then abnormality is
detected.
1
Check if transmission wire of indoor unit,
FRESH MASTER, LOSSNAY, or remote
controller is not connected to terminal block
for central control (TB7) of outdoor unit.
2
Check if transmission wire of indoor unit,
FRESH MASTER or LOSSNAY is not con-
nected to terminal block for transmission
wire of outdoor unit.
3
Check if terminal block for transmission wire
(TB3) and terminal block for central control
(TB7) is not connected.
4
Check transmission waveform or noise on
transmission wire.
<M-NET communication error>
Note: “Indoor unit” in the text indicates M-NET board in outdoor unit.
A6
(6606)
Communication error with communica-
tion processor
Defective communication between unit
processor and transmission processor
Note: The address and attribute display at
remote controller indicate the con-
troller that detected abnormality.
1
Data of transmission proces-
sor or unit processor is not
transmitted normally because
of accidental trouble such as
noise or thunder surge.
2
Address forwarding from unit
processor is not transmitted
normally because of defective
transmission processor hard-
ware.
Turn off the power supply of outdoor unit and
indoor unit and FRESH MASTER or LOSSNAY
at the same time for 2 minutes or more, and
turn the power on again. System returns to nor-
mal if abnormality was accidental malfunction.
If the same abnormality occurs again, abnor-
mality-detected controller may be defective.
Check Code