Mitsubishi Electric PRH-P8MYA Technical & Service Manual page 66

Abnormal- Meaning of abnormality display and
ity display abnormality troubleshooting
Remote controller communica-
tions receive abnormal (remote
controller).
1) When transmission from refriger-
ant address "0" IC is not received
EO normally even once in 3 minutes,
an abnormality is recognized.
2) When a slave remote controller
does not receive even one signal
in 2 minutes, an abnormality is
recognized.
Remote controller communication
send abnormal (remote controller)
1) When the remote controller can
not confirm that the transmission
circuit is idle in 6 seconds, an ab-
E3
normality is recognized.
2) When the remote controller can-
not complete 30 continuous trans-
missions, an abnormality is rec-
ognized.
Indoor-outdoor communication
receive abnormal
(Outdoor-side unit)
When the outdoor-side controller
E8
can not receive normally even
once in 3 minutes, an abnor-
mality is recognized.
Indoor-outdoor communication
send abnormal
(Outdoor-side unit)
1) When the outdoor-side controller
detectes reception of 30 consecu-
tive "0" even through "1" was re-
E9
ceived, an abnormality is recog-
nized.
2) When the outdoor-side controller
can not confirm that the transmi-
ssion circuit is idle in 3 minutes,
an error is recognized.
Check code undefined
Displayed when an undefined check
EF code is received.
Cause
(1) Remote controller send/receive
circuit faulty.
(2) Refrigerant address "0" indoor-side
controller board send/receive circuit
faulty.
(3) Noise entered on remote controller
transmission line.
(1) Remote controller send/receive circuit
faulty.
(2) Noise entered on remote controller
transmission line.
(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 entered on indoor/outdoor con-
nection wire.
(1) Outdoor-side controller board send/
receive circuit faulty.
(2) Noise entered at power supply.
(3) Noise entered on indoor/outdoor con-
nection wire.
(1) Noise entered on remote controller
transmission line.
(2) Noise entered on indoor/outdoor con-
nection wire.
- 63 -
Judgment method and remedy
Perform remote controller diagnosis.
Take the following action based on the di-
agnosed result:
a) [RC OK] display
Remote controller normal.
Turn power off and on and check.
If "H0" remains on for 4 minutes or
longer, replace indoor controller board.
b) [RC NG] display
Replace remote controller.

c) [RC E3] display
Noise, etc. probable

[ERC00-66] cause.

(1) Check for disconnected or loose
indoor-side unit or outdoor-side unit
indoor/outdoor connection wire.
(2)-(4)
Turn power off and on and check.
If abnormality displayed again, replace
indoor controller board or outdoor-side
controller board.
(1)(2)(3)
Turn power off and on and check.
If abnormality displayed again, replace
indoor controller board or outdoor-side
controller board.
(1)(2)
Turn power off and on and check.
If abnormality displayed again, replace
indoor-side controller board or
outdoor-side controller board.