Troubleshooting; Service Flowchart - Mitsubishi Electric Lossnay LGH-50RVS-E Handbook

6. Troubleshooting

Work precautions
• Before starting the service, the power supply isolator must be turned off. Pay sufficient attention to avoid elec-
tric shock or injury.
• When removing or touching the cables, circuit boards or other parts, be sure to turn off the power supply isolator.
• Even after the power supply isolator is turned off, the capacitor on the circuit board retains high voltage for a while.
Therefore, before servicing, wait for at least five minutes, and then use a tester to check that the voltage has dropped.
• Once the power supply is turned off, be sure to wait for at least five minutes before turning the power back on
again.
• When servicing, power supply to M-NET must be turned off. Live-line working may cause a circuit board failure.
• When servicing, recreate the malfunction two or three times before starting repairs.
• When servicing, always keep proper footing.
• When disconnecting the motor connectors, make sure that the power supply is turned off. Even when the fan
motor is stopped, disconnecting the live-line connectors will cause a motor malfunction.
• When removing the circuit board, always hold it at both ends and remove carefully in order not to apply force to
the surface mounted parts.
• When removing the circuit board, be careful of the metal edges on the board.
• When removing or inserting the connectors for the circuit board, hold the entire housing section. Never pull on
the lead wires.
• When circuit board failure is considered to be a cause, check closely for any broken section on the copper foil
patterns, burning or discoloration of parts.
• If the circuit board is replaced, make sure that the switch settings on the new board are the same as the old board.
• Be sure to connect the power supply wires correctly.
• When carrying out wiring, power supply to M-NET must be turned off, otherwise it will cause a malfunction.

6-1 Service flowchart

After checking the check items below, follow the troubleshooting for servicing.
Applicable Device
Lossnay Heat recovery Ventilator
Lossnay Remote Controller
No. Preliminary check item
1 Product information
2 Fault status
3 Frequency of fault
occurrence
4 Timing of fault occurrence • Remote controller operation performed before fault occurrence
5 System settings
6 System drawings
LGH-50RVS-E, LGH-80RVS-E, LGH-100RVS-E
PZ-62DR-E, PZ-43SMF-E
• Model name of the product
• Serial number of the product, manufacturing lot number of the circuit board
• Microcomputer software version marked on the circuit board
• Fault status (For example, the fan does not operate.)
• Error code display on the remote controller
• Operation setting of the remote controller (ventilation mode setting, fan
speed setting, etc.)
• Frequency of fault occurrence (frequency of date and time of occurrence,
regularity of occurrence, etc.)
• Operating time up to fault occurrence
• Date of start of use, date of fault occurrence
• Operating status, etc.
• Function selection switch settings and address setting of the product
• Model name and address setting of the Lossnay remote controller or system
controller, etc.
• Function settings on PZ-62DR-E when PZ-62DR-E is used
• System Configuration
• Wiring
• Record of the Lossnay function setting statuses
─ 10 ─
Applicable Model
Details