Service manual

6-18
6.5.5 Automatic Back up for supply / return air temperature sensors
When the unit is equipped with the data recorder sensors, the following emergency operations are
available.
When the DRS and DSS are used for the emergency operation, DATA RECORDER SENSOR ON/OFF
SETTING to be set OFF. (Refer to page 3-30, basic function setting mode
.)
RS: Return air temperature sensor DRS: Data recorder return air temperature sensor
RRS: Recorder return air temperature sensor
SS: Supply air temperature sensor DSS: Data recorder supply air temperature sensor
RSS: Recorder supply air temperature sensor
Malfunction code Abnormal point Unit back-up operation
E401 SS
Supply air temperature sensor (SS) for control
malfunction
Chilled mode:
Back-up operation with DSS
Frozen mode:
only malfunction code indication
E402 DSS
Data recorder supply air temperature sensor (DSS)
malfunction
Only malfunction code indication
E401
E402
Both SS and DSS malfunction Chilled mode:
Back-up operation with RS –2˚C.
Frozen mode:
only malfunction code indication
E403 RS
Return air temperature sensor (RS) for control
malfunction
Chilled mode:
only malfunction code indication
Frozen mode:
Back-up operation with DRS
E404 DRS
Data recorder supply air temperature sensor (DRS)
malfunction
Only malfunction code indication
E403
E404
Both RS and DRS malfunction Chilled mode:
only malfunction code indication
Frozen mode:
Back-up operation with SS +5˚C
H006 Chilled mode:
Temperature difference is 2 ˚C or more between SS
and DSS or more than one hour.
Only malfunction code indication
Frozen mode:
Temperature difference is 2 ˚C or more between RS
and DRS or more than one hour.
Only malfunction code indication