m908 User Manual, Rev. G
5.23.2
PSU Error
The PSU contains a processor that monitors the voltages from the two redundant power
supply modules. If any of these voltages fall outside of the permitted tolerance then this will be
communicated to the ACU and a warning will appear on the RCU display screen. If this error
occurs contact Grace Design Technical Support
5.23.3
Communication Error
The RCU and ACU communicate over a balanced RS485 serial link. If the RCU experiences a
communication error this screen will be displayed.
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Illustration 30: ACU Temperature Error
Illustration 31: PSU Error