Troubleshooting - Mitsubishi Electric FRESH MASTER GUF-50RD4 Handbook

7. Troubleshooting

Work precautions
• When servicing, be sure to recreate the malfunction two or three times before starting repairs.
• When servicing, always keep proper footing.
• When servicing, make sure that the power supply isolator is off, so as no electrical shock or injury to occur.
Pay sufficient attention when working on the product.
• Always connect the power wires properly.
• When removing the circuit board, always hold it at both ends and remove carefully so as 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.
• If it is thought that there is a printed circuit board malfunction, check for disconnected wires in the print pat-
tern, burnt parts or discoloration.
• If the printed circuit board is replaced, make sure that the switch settings on the new board are the same as
the old board.
• When servicing or checking around the humidifying unit, make sure to close the service valve.
( 1 ) Troubleshooting 1: The system will not start properly.
Initialization checklist from installation to operation ( Table 1 )
After checking the system, check the checkpoints listed below.
Power supply ( Table 1-1 )
No.
1 Is the main power supply on?
2 Do the main power supply switching capacity and wiring diameter meet
specification?
3 Is the specified power supply of 220 to 240 V AC (220 V AC for GUF-
-60) connected to the power supply terminal ( TM1 ) ?
100RDH
4
4 Has the fuse ( FUSE 1 ) on the circuit board blown?
5 Are connector CNT of the transformer primary (input) and connector CN3T of
the transformer secondary (output) on the circuit board securely connected?
6 Is the power supply wiring incorrectly wired, or is there a faulty connection? Make secure connections.
7 Is power display LED1 (red) on the circuit board unlit?
Transmission cables (Table 1-2)
Check the following checkpoints when connecting with the remote controller or M-NET controller.
No.
1 Do the transmission cables meet regulations? ( Type, diameter )
2 Is the transmission cable wired at least 5 cm away from the power supply
cable?
3 Are multiple transmission or signal cables wired to the same power cable
duct?
4 Are multiple transmission cables wired with multi-core cables?
5 Are the transmission cables securely connected to the terminals?
6 Are the address switches on the circuit board (SW11 and SW12) set to
the correct number?
7 Are the transmission cables connected to the specified terminal blocks?
MA remote controller: TM2 1, 2
M-NET controller: TM2
Checkpoint
Checkpoint
,
A B
─ 11 ─
Action
Turn on the main power supply.
Use specified items.
Connect the specified power sup-
ply.
Replace the circuit board.
Connect them securely.
Check the above checkpoints.
Action
Use specified cables.
Wire the transmission cable at least 5
cm away from the power supply cable.
Wire the transmission cables away
from the signal cables.
Use suitable cables to wire the
transmission cables so that they
are separated from one another.
Connect them securely.
Make the setting so that the ad-
dress does not duplicate that of
other devices within M-NET control.
Connect them to the specified
terminal blocks.