3com 4500 POE drops

[redbowtie]

I have 3com 4500 POE switches running Shoretel VoIP phones. Occasionally when a thunder storm goes through the area the switches will drop or stop supplying POE power to all of the ports. To get the POE power to come back on I disable POE on all ports the enable POE on all ports. The switches are plugged into APC Smart-UPS so I don't think this is caused by an AC power problem.

Has anyone else had this problem? Any ideas on how I can trouble shoot this problem?

 

[IRudebwoy]

Is your APC sized correctly for the power draw of your equipment. During a non-critical time unplug the UPS for a few seconds to see if it can keep your switches powered.

Otherwise, make sure your equipment is properly grounded. Any transient voltage will effect your switches and will eventually damage them beyond repair. Have you blown any ports? If you have, check your ground.

Have Fun!

 

[SYQUEST]

APC provides a ground/bond screw on the back of the Smart-UPS product for this purpose, which is mentioned in the documentation. (It seems most folks never read this stuff.)

Proper GROUNGING/BONDING is important and a requirement per NEC!

....JIM....

 

[redbowtie]

These switches are plugged into a 2200XL that has 58% load on it. Plenty of power available.
Never blown any ports. The non POE devices continue to operate so the ethernet function on the switches is not affected.

 

[wkennard]

We had big problems with POE resetting on these. A somewhat cryptic hint from a chinese engineer, pointed us to upgrading the POE firmware. We went to 5.03.s19 and it helped immensely.
We never tied it to thunderstorms though. Our switch closets
power is tied to our Liebert UPS that runs the datacenter.