Mitsubishi Electric PUHY-HP144TSHMU-A Service Handbook page 142

[ IX Troubleshooting ]
1. Error Code
4106
Transmission power supply fault Error detail FF (Outdoor unit)
2. Error definition and error detection method
Transmission power output failure
3. Cause
1) Wiring failure
2) Transmission power supply cannot output voltage because overcurrent was detected.
3) Voltage cannot be output due to transmission power supply problem.
4) Transmission voltage detection circuit failure
4. Check method and remedy
Check the following items on all outdoor units in the same refrigerant circuit.
1) Turn off the outdoor unit, disconnect the wiring from TB3 and TB7, and turn the power back on. Confirm that the voltage of at
least 25 V is output to each TB, 120 seconds after turning on the power. If the male power supply switch connector is con-
nected to CN41, no voltage will be output to TB7.
If no voltage is output when item 1) above is checked
2) Confirm that CN102, CNS2, and CNIT, which connect the control board and M-NET board, are properly connected.
Check items 1) and 2) above, and if no voltage is output, either the control board or the transmission power board has a prob-
lem.
If voltage is output when items 1) and 2) above are checked.
3) Confirm that the indoor/outdoor transmission line and M-NET control are not shorted out.
4) Confirm that the transmission line for centralized control and indoor/outdoor transmission line are not mixed up.
5) Confirm that only one unit is supplying power to the transmission line for centralized control. (Confirm that the male power
supply switch connector is connected to CN40 on only one outdoor unit.) Confirm that no other power supply units or outdoor
units (LED1 on the transmission power board is lit.) are supplying power to the given indoor unit system.
1. Error Code
4106
Transmission power supply fault Other than Error Detail Code FF (Outdoor unit)
2. Error definition and error detection method
Transmission power reception failure
3. Cause
One of the outdoor units stopped supplying power, but no other outdoor units start supplying power.
4. Check method and remedy
Check the following items on all outdoor units in the same refrigerant circuit.
1) Turn off the outdoor unit, disconnect the wiring from TB3 and TB7, and turn the power back on. Confirm that the voltage of at
least 25 V is output to each TB, 120 seconds after turning on the power. If the male power supply switch connector is con-
nected to CN41, no voltage will be output to TB7.
If no voltage is output when item 1) above is checked
2) Confirm that CN102, CNS2, and CNIT, which connect the control board and M-NET board, are properly connected.
Check items 1) and 2) above, and if no voltage is output, either the control board or the transmission power board has a prob-
lem.
If voltage is output when items 1) and 2) above are checked.
3) Confirm that the indoor/outdoor transmission line and M-NET control are not shorted out.
4) Confirm that the transmission line for centralized control and indoor/outdoor transmission line are not mixed up.
5) Confirm that only one unit is supplying power to the transmission line for centralized control. (Confirm that the male power
supply switch connector is connected to CN40 on only one outdoor unit.) Confirm that no other power supply units or outdoor
units (LED1 on the transmission power board is lit.) are supplying power to the given indoor unit system.
HWE0716A
- 133 -
GB