H3C Technologies H3C WX5000 Series Access Controllers User Manual

Page 75

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B-2

3) Pay adequate attention if the red LED is on. You should correctly locate the problem, whether it is

caused because the ground cable of the arrester is not well grounded or because the live and zero

wires are connected in reverse direction.

4) You may use a multimeter to examine the polarity at the power receptacle of the arrester:

z

With the power receptacle facing you, if the multimeter displays that the left wire is the zero wire

and the right is the live wire, it means that the PE terminal of the arrester is not well grounded.

z

Otherwise, it means that the power receptacle of the arrester is set to the reverse polarity. In this

case, open the power receptacle of the arrester and correct the polarity. After that, if the red LED

still alarms, it means that the arrester is not well grounded yet.

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