Hello everyone!
This post will introduce you a case of equipment grounding. I hope it will be helpful to everyone.
Issue Description
After the power supply device EFS4890 of the OptiX OSN 1500 is powered on, the equipment is powered on normally. However, the equipment personnel finds that the cabinet is also electrified.
Handling Process
1. Check the power supply environment of the equipment room. It is found that the cabinet is not grounded and the power strip connected to the EPS4890 is not grounded. The power supply environment of the equipment room does not meet the requirements.
2. Analyze the power supply of the cabinet. Connect a ground cable to the equipment room from the outside. Use a multimeter and connect one end to the cabinet and the other end to the ground cable. The voltage of the cabinet is 99 V, as shown in the following figure.
3. Further analyze the reason why the cabinet is electrified. Test the voltage of the power supply circuit breaker to the power strip, the voltages of the live wire to the power cable are 220 V, and those of the neutral wire to the ground cable is 0. Therefore, the power supply is normal and no issue occurs.
4. There are other vendors' devices in the cabinet (the subracks of the devices are in contact with the cabinet), as shown in the following figure. When other devices are separately powered on, the cabinet is also electrified. When more devices are powered on, the voltage of the cabinet goes up to 160 V. After all devices are powered off, the cabinet is not electrified.
5. When the device is powered on, connect the ground cable to the cabinet. The voltage of the cabinet changes to 0. The current between the test cabinet and ground cable is almost 0. The fault is caused by the induced voltage, which causes the cabinet to be electrified.
Root Cause
The devices in the equipment room are not properly grounded.
Solution
Ground the cabinet and devices properly.
Suggestions
The grounding of the equipment room should meet the requirements, as shown in the following table.
That's all. If you also encounter this problem, please leave a message and share your process.
Thank you!
