Mitsubishi Electric CITY MULTI PUHY-400YMF-C Service Handbook page 177

Checking
Meaning, detecting method
code
7102 Connected unit count over
7105 Address setting error
• Erroneous setting of OC unit
address
Trouble source:
Indoor unit
7110 The indoor unit will not operate
because it is not correctly con-
nected to the outdoor unit of the
same refrigerant system.
7111 Remote control sensor error
Error not providing the tempera-
ture designed to remote control-
ler sensor.
Trouble source:
Indoor unit
7130 Different Refrigerant unit
connected error
If different units within one system are using different types of refrigerant as shown in table 1 below, the system will not
operate correctly.
Table1
Example 1
Variable capacity unit R407C
Constant capacity unit R407C
Indoor units
R22 only
Cause
2) Disconnection of transmission
wiring at Outdoor unit.
3) Short circuit of transmission line in
case of 2) and 3), remote controller
displays "HO".
4) When PUHN is connected with
SW4-6=OFF.
5) When PUHN is not connected with
SW4-6=ON.
1) Setting error of Outdoor unit ad-
dress.
The address of Outdoor unit is not
being set to 51~100.
1) The transmission booster is defec-
tive, has disconnected wires, or the
power has been cut-off.
2) The transmission booster and out-
door unit power supplies have been
cut-off.
1) In case when the old type remote
controller for M-NET is used and the
remote controller sensor is de-
signed on indoor unit. (SW1-1
turned ON)
(See Table 1)
Refrigerant type
Example 2 Example 3
R407C R22
R22 R407C
– –
-174-
Checking method & Countermeasure
d) Check for the model total (capacity code total)
of indoor units connected.
Check that the address of OC unit is being set to
51~100.
Reset the address if it stays out of the range, while
shutting the power source off.
a) Check that the power has not been cut-off due
to the power supply of transmission booster
being connected to the indoor unit switch.
(The air conditioner will not operate correctly if
the power supply of transmission booster is
not turned on.)
→ Reset the outdoor unit power supply.
a) Replace the old remote controller by the new
remote controller.
Use the same type of refrigerant in all units
included in the system.