Mitsubishi Electric Mr.SLIM PUZ-HA24NHA Service Manual page 36

From the previous page.
Check code Abnormal points and detection method
5. If displayed address or attribute is
FRESH MASTER,
Indoor unit detects abnormality when
indoor unit transmitted to FRESH
MASTER and there was no reply (ACK).
6. If displayed address or attribute is
LOSSNAY,
Indoor unit detects abnormality when
indoor unit transmitted to LOSSNAY and
there was no reply (ACK).
A7
(6607)
7. If displayed address or attribute is nonex-
istent,
M-NET NO RESPONSE
Abnormal if a message was transmitted and
there were reply (ACK) that message was
received, but response command does not
return. Transmitting side detects abnormal-
ity every 30 seconds, 6 times continuously.
Note: The address and attribute displayed
at remote controller indicate the con-
troller that did not reply (ACK).
A8
(6608)
OCH721A
Cause
1 During sequential operation
of indoor unit and FRESH
MASTER of other refrigerant
system, if indoor unit transmits
to FRESH MASTER while out-
door unit power supply of same
refrigerant system with FRESH
MASTER is turned off or within
2 minutes of restart, abnormal-
ity is detected.
2 Contact failure of transmission
wire of indoor unit or FRESH
MASTER
3 Disconnection of transmission
connector (CN2M) of indoor
unit or FRESH MASTER
4 Defective transmitting receiving
circuit of indoor unit or FRESH
MASTER
1 If the power supply of
LOSSNAY is turned off, indoor
unit detects abnormality when it
transmits to LOSSNAY.
2 During sequential operation
of indoor unit and LOSSNAY
of other refrigerant system,
if indoor unit transmits to
LOSSNAY while outdoor unit
power supply of same refriger-
ant system with LOSSNAY is
turned off or within 2 minutes of
restart, abnormality is detected.
3 Contact failure of transmission
wire of indoor unit of LOSSNAY
4 Disconnection of transmission
connector (CN2M) of indoor unit
5 Defective transmitting receiv-
ing circuit of indoor unit or
LOSSNAY
1 The unit of former address
does not exist as address
switch has changed while the
unit was energized.
2 Abnormality is detected
when indoor unit transmitted
because the address of FRESH
MASTER and LOSSNAY are
changed after sequential opera-
tion of FRESH MASTER and
LOSSNAY by remote controller.
1 Transmitting condition is
repeated fault because of noise
and the like.
2 Extension of transmission wire
voltage and signal is caused by
over-range transmission wire.
• Maximum distance ····· 656 ft
[200 m]
• Remote controller line ···(39 ft
[12 m])
3 Extension of transmission wire
voltage and signal is caused by
type-unmatched transmission
wire.
Type·····
With shield wire-
CVVS, CPEVS
With normal wire (no shield)-
VCTF, VCTFK, CVV
CVS, VVR, VVF, VCT
Diameter ···1.25 mm [AWG16]
2
or more
4 Accidental malfunction of
abnormality-detected controller
36
judgment and action
Same as mentioned in "A7" of the previous
page.
1 Check transmission waveform or noise on
transmission wire.
2 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. If mal-
function was accidental, the unit returns to
normal. If the same abnormality occurs again,
controller of displayed address and attribute
may be defective.