Nokia 7210 SAS-M Series - 2.4.4.1 DC power source failure detection

System Overview
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7210 SAS-M CHASSIS INSTALLATION GUIDE
3HE 10089 AAAA TQZZA Edition 01 Issue: 07
2.4.4.1 DC power source failure detection
The 7210 SAS-M platform provides capability to detect DC power source (–48V or
+24V source) failure. The 7210 SAS-M chassis allows two DC power sources to be
connected to the chassis. If the system detects that the DC power source has failed,
it raises a critical alarm (the Critical LED is lit and the Critical Alarm output pin is
triggered) and the system's status LED turns amber and blinks. The alarm is cleared
if the DC power source is restored. No user configuration is required to enable this
feature. The software enables this feature automatically by detecting the capability
of the hardware platform.
The system has two slots for AC or DC power supplies. It associates the DC power
supply in the top slot with power source feed A (–48V or +24V Ret-A on the chassis)
and the DC power supply in the bottom slot with power source feed B (–48V or
+24VRetB on the chassis). The system detects the failure of power source feed A
only if the DC power supply is plugged into the top slot. Similarly, the system detects
the failure of power source feed B only if the DC power supply is plugged into the
bottom slot. The trap message generated by the system indicates that there was an
input failure for the power supply associated with the power input feed that failed.
Table 5 lists the conditions under which the system detects a power source failure.
Note:
• New traps must be explicitly enabled by the user and are suppressed by default.
• The power feeds are summed up internally before feeding the power supply units.
Therefore, the DC power supply units will output power even if only one of the power
source feeds are available.
• Please refer to the release notes to determine which software release supports this
feature.
Table 5 Power Source Failure Detection Capability
Power Feed A
(Available/
Failed)
Power Feed B
(Available/
Failed)
Power
Supply in
Top Slot
(PS1)
Power
Supply in
Bottom
Slot
(PS2)
Alarm
Generated
(Yes/No)
Notes
Available Available DC DC No —
Available Failed DC DC Yes PS2 input failure / PS2 output
OK
Failed Available DC DC Yes PS1 input failure / PS1 output
OK