Troubleshooting - Toshiba MMU-AP0071MH Service Manual

7. TROUBLESHOOTING

7-1. Troubleshooting Summary
1. Before troubleshooting
1) Applied models
Q
S-MMS Multi type models
Indoor unit: MMX-APXXX,
Outdoor unit: MMY-MAPXXXHT8, MMY-MAPXXXT7
R
Super Heat Recovery Multi type models
Indoor unit: MMX-APXXX,
Outdoor unit: MMY-MAPXXXFT8
S
Mini-S-MMS Multi type models
Indoor unit: MMX-APXXX,
Outdoor unit: MCY-MAPXXXHT, MCY-MAPXXXHT2D
2) Required tools / measuring devices
• Screwdrivers (Philips, Minus), spanner, radio pinchers, nipper, push pin for reset switch, etc.
• Tester, thermometer, pressure gauge, etc.
3) Confirmation before check (The following items are not troubles.)
No. Operation
1 Compressor does not operate.
2 Indoor fan does not work.
3 Outdoor fan does not rotate, or
fan speed changes.
4 Indoor fan does not stop.
5 Start/stop operation on remote
controller is unavailable.
6 ——
2. Troubleshooting procedure
When a trouble occurred, advance the check operation in the following procedure.
Trouble
NOTE) While a check operation is performed, a malfunction of the microprocessor may be caused due to
condition of the power supply or the external noise. If there is any noise source, change wires of the
remote controller and signal wires to shield wires.
• Is not delayed for 3 minutes? (3 minutes after compressor-OFF)
• Is not thermostat OFF?
• Is not the fan operating or timer?
• Is not the system initially communicating?
Heating operation cannot be performed under condition of outside tempera-
ture 21°C or higher.
Cooling operation cannot be performed under condition of outside tempera-
ture –5°C or lower.
• Is not the cold draft prevention being controlled in heating operation?
• Is not low cooling operation being controlled?
• Is not a defrost operation being performed?
• Is not after-heat elimination operation being controlled after heating opera-
tion?
• Is not auxiliary unit or remote control being operated?
• Is connecting wire of indoor unit or remote controller correct?
Check the check display
on the interface P.C. board
of the outdoor unit.
Check items
Check position or part
in which trouble occurred.
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