88" Appears On The Lcd - Mitsubishi Electric R410A Service Handbook

[8-2 ME remote Controller Problems ]
8-2-4

"88" Appears on the LCD.

1. Phenomena
"88" appears on the remote controller when the address is registered or confirmed.
2. Cause, check method and remedy
An error occurs when the address is registered or con-
firmed. (common)
1. A wrong address is set to the unit to be coupled.
2. The transmission line of the unit to be coupled is dis-
connected or is not connected.
3. Circuit board failure of the unit to be coupled
4. Improper transmission line work
Generates at interlocking registration between LOSS-
NAY and the indoor unit
5. The power of LOSSNAY is OFF.
Generates at confirmation of controllers used in the
system in which the indoor units connected to different
outdoor units are grouped
6. The power of the outdoor unit to be confirmed has
been cut off.
7. Transmission line is disconnected from the terminal
block for central control system connection (TB7) on
the outdoor unit.
8. When the indoor units connected to different outdoor
units are grouped without MELANS, the male power
supply connector is not connected to the female
power supply switch connector (CN40) for the trans-
mission line for centralized control.
9. The male power supply connectors on 2 or more out-
door units are connected to the female power supply
switch connector (CN40) for the transmission line for
centralized control.
10. In the system to which MELANS is connected, the
male power supply connector is connected to the fe-
male power supply switch connector (CN40) for the
transmission line for centralized control.
11. Short circuit of the transmission line for centralized
control
HWE14080
Cause
- 244 -
Check method and remedy
(1) Confirm the address of unit to be coupled.
(2) Check the connection of transmission line.
(3) Check voltage of the terminal block for transmission
line of the unit to be coupled.
1) Normal if voltage is between DC17 and 30V.
2) Check (5) in case other than 1).
(4) Check for the main power of LOSSNAY.
(5) Check the power supply of the outdoor unit which is
coupled with the unit to be confirmed.
(6) Check that the transmission line for centralized
control (TB7) of the outdoor unit is not disconnect-
ed.
(7) Check voltage of the transmission line for central-
ized control.
1) Normal when voltage is between 10V and 30V
2) Check 8 - 11 described on the left in case other than
1).
GB