The OSN1500B TEMP_ALARM alarm indicates the single board ambient temperature overrun alarm. This alarm is reported if the single board detects that the ambient temperature exceeds the set temperature threshold. Alarm level: minor, alarm type: environment, alarm parameter: 0x01: temperature exceeds the upper limit. 0x02: temperature exceeds the lower limit. After generating this alarm, if the temperature is too high (low) and damages the optical module, the service will be interrupted.

Problem Description

An OSN1500 device reports a TEMP_ALARM alarm, and the network administrator checks the CXL veneer for a reported temperature of 80 degrees. The ambient temperature of the server room is around 10 to 15 degrees Celsius, and there is no high-power heat source near the OSN1500 equipment. OSN1500 is installed in a 19-inch cabinet, and there is a space of about 2 centimeters between the side of the OSN1500 frame and the side door of the cabinet, and there is no obstacle such as cables, so cleaning up the dust net, replacing the fan, and replacing the CXL single board can not solve the problem completely.

Alarm Message

TEMP_ALARM

Processing

After cleaning the flocculent dust on the mesh of the left side panel of OSN1500, the cooling airflow increased significantly, the temperature of the equipment decreased, and the temperature detected by the CXL single board stabilized at about 30 degrees after 24 hours, and the problem was solved.

Failure causes

The ambient temperature of the single board is too high.

1. If it is the business veneer that reports this alarm, go to 2.b.
2. Check the subrack fan operation status. For details, see the FAN_FAIL alarm processing steps to deal with it.
3. Query whether the alarm TEMP_ALARM is eliminated. If the alarm is not eliminated, replace the faulty veneer. For details, see Task Set Field Replacement of Veneer Boards.
4. Query whether the alarm is canceled. If the alarm is still not canceled, contact Huawei engineers.
5. The operating environment is normal, and the replacement of the single board precludes abnormal heat generation, so analyze the cause of the failure in the poor heat dissipation of OSN1500.
6. Open the handle bar of the empty slot and find that there is basically no wind blowing out, and analyze that the heat dissipation air duct is abnormal.
7. Analyze OSN1500 cooling channel, cold air through the OSN1500 frame left mesh, dust net to the fan, after the veneer hot air through the frame right mesh discharge.
8. Dust net is a steel wire type dust net, no dust.
9. Fan operation is normal.
10. Checking the mesh on the left panel of the OSN1500 frame, it is found that a large amount of flocculent dust is attached to the outside of the frame, and the mesh is basically blocked, resulting in cold air not being able to enter the device to form an effective heat dissipation.

Suggestions and Summary

1, OSN1500 equipment cooling channel including the frame side panels, when the operating environment is dusty, the mesh holes in the side panels are easily blocked resulting in poor heat dissipation. In general maintenance and troubleshooting, only pay attention to cleaning the dust mesh but neglect the cleaning of the side panels, which affects the heat dissipation ability of the equipment.

2, the left side panel of the frame is the air inlet, the outer side is easy to attach dust and not easy to find.

3, OSN1500 installation, need to pay attention to avoid blocking the side panels affect the heat dissipation, must be reserved part of the space.

This chapter of related technical information and SDH equipment troubleshooting process provided by Shenzhen Optical Transmission Network Technology Co., Ltd ( www.opticaltrans.com), reproduced please retain! Huawei SDH Optical Transmission Equipment,SDH Transmission Equipment Sales