Cisco Systems ONS 15327 2.6.137 PWR-A

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Cisco ONS 15327 Troubleshooting Guide, R3.4

March 2004

Chapter2 Alarm Troubleshooting

Alarm Procedures

•All LEDs blink once and turn off.

•The ACT/STBY LED is green (active).

Step 7 If the alarm does not clear, log onto http://www.cisco.com/tac for more information or call TAC

(1-800-553-2447).

2.6.137 PWR-A

•Minor (MN), Non-Service Affecting (NSA)

An NE Power Failure at Connector A alarm indicates that the power is out of the specified 48 VDC input

range and is either too high (overvoltage) or too low (undervoltage), requiring you to check the incoming

power feed or separate power distribution equipment, or both. The PWR-A ala rm m ay als o b e rai sed

before actual loss of power in a discharging power plant problem and before fu ll loss of incoming power.

Overvoltage or undervoltage can be caused by incoming DC power problems such as power rectifier

failure, faulty power cabling, or a blown fuse.

Cisco encourages the use of separate DC power feeds from separate D C power pla nts o r AC power

rectifiers to ensure power redundancy to the feeds. Using a single DC power source for both

MIC-A/PWR-A and MIC-B/PWR-B creates a risk through the single point of possible failure. Using

dual power feeds removes this risk liability.

Warning

Hazardous energy level available at the power source and power connection. Do not bridge across

battery terminals or bridge battery terminal to ground; metal objects heat up and can cause serious

burns or weld the metal object to the terminals.

Step1 Determine whether the PWR-A alarm is occurring alone or in conjunction with the PWR-B alarm, and

determine whether MIC A and MIC B are using one single or t wo sep arat e p ower suppli es.

Step2 If you are usi ng se pa rat e power sour ce s for t he M IC A a nd MIC B power co nne cto rs an d t he PWR- A

alarm occurs without the PWR-B alarm, inspect the incoming voltage to the MIC A connector using site

practices. The alarm can be caused by problems such as pow er rec tifier failure, faulty power cabling, or

a blown fuse, and correct these issues. Solve th es e pro bl ems b efo r e co nt inui ng .

You can verify the power connection continuity and the power source output with a voltmeter using the

procedures in the CiscoONS 15327 Procedure Guide.

Step3 If you are using a single power source for both the MIC A and MIC B cards an d only the PWR-A alarm

is occurring, an electrical cable continuity or connection problem may be to blame. Check for these

problems and correct them if necessary.

Step4 If you are using separate power sources for each MIC card and the PWR-A alarm occurs in conjunction

with the PWR-B alarm, it is likely that both incoming power feeds or power plants are failing. Check for

these problems according to site practice and correct as necessary.

Step5 If you are using a single power source for both MIC cards and both the PWR-A and PWR-B alarm s are

raised, problems with both power feeds may be to blame, but a power plant failure is more likely. Check

for these problems according to site practice and correct as necessary.