ABB AC 800M

Section 5 Maintenance PM861/PM864 Processor Unit in Redundant Configuration
3BSE 027 941 R301 129
PM861/PM864 Processor Unit in Redundant Configuration
Internal Battery / SB821 External Battery
Table 22. PM861/PM864 Redundant Configuration – Fault-Finding Procedure
Fault Possible Cause and Corrective Action
DUAL LED is OFF on both
CPUs
The CPUs are in the process of being re-started
or configured. Allow time for this to finalize.
RCU Link Cable disconnected.
• Connect the RCU Link Cable.
Different Control Software in the two CPUs.
• Upgrade the CPUs with the same control
software.
Table 23. Internal / SB821 External Battery – Fault-Finding
Fault Possible Cause and Corrective Action
B(attery) LED indicator on
PM8xx processor unit is
flashing
• Renew the PM8xx internal battery
or, (if fitted)
• Check external battery connections.
If condition persists
• Renew the External battery, see SB821
External Battery Unit on page 123.
The system time is incorrect
following a power failure
• Ensure that the software installed supports
the real-time clock.
• Renew the External Battery, see SB821
External Battery Unit on page 123.