Mitsubishi Electric CITY MULTI PUMY-P112VKM6 Service Manual page 70

6607 (A7): No ACK error
Abnormal points and detection methods
■ The address/attribute of Lossnay was displayed:
An abnormality detected by the indoor unit if it received no
ACK when transmitting signal to the Lossnay.
■ The displayed address/attribute is not assigned to any controller.
OCH790 _70
Causes and checkpoints
• An abnormality is detected when the indoor unit trans-
mits signal to Lossnay while the Lossnay is turned OFF.
• While the indoor unit is operating with Lossnay in a
different refrigerant system, an abnormality is detected
when the indoor unit transmits signal to the Lossnay
while the outdoor unit in the same refrigerant system as
the Lossnay is turned OFF, or within 2 minutes after it
turned back ON.
• Contact failure of indoor unit or Lossnay transmission
line
• Disconnection of transmission connector (CN2M) on
indoor unit
• Malfunction of sending/receiving circuit on indoor unit or
Lossnay
• The previous address unit does not exist since the ad-
dress switch was changed while power was on.
• The abnormality was detected when the indoor unit sent
or received signal because the address of the Fresh
Master/Lossnay was changed after a setting for linking
the Fresh master/Lossnay was made on the remote
controller.
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