IP Phone "Shock"

[adignan]

I know this topic has been discussed previously but there has been no resolution. Anyone from Cisco care to comment? I have had more than a few complaints on this.

[ducdo]

which IP phone model ? do you use Inline Power?

[adignan]

Inline Power - Yes 7940 or 7960's

[ducdo]

I had the same problems...... any Cisco guys outthere can response to us? ... if not , I think we're seriously looking at other vendors?

Thanks

[kthorngr]

- Have you isolated the problem to people on the swich/swich blade?

- Does this problem happen to more that one person?

- Have you checked the area where the complaints come from for ESD related items?

- Does this problem seem to occur only when the weather is dry?

- Is the switch properly grounded?

This is an important issue. My recommendation would be to gather some information above and open a TAC case. I would also ask for a failure analysis of any equipment you return.

[Wes Sisk]

Andrew,

I have worked a few cases of reported shock by ipphones. My findings from the cases:

1. c6k providing inline power was not correctly grounded to an earth ground with the ground lug.

http://www.cisco.com/en/US/partner/products/hw/switches/ps700/products_installation_guide_chapter09186a008007eb6d.html#1058223

2. high static environment - customer reported shock by ipphone, after several days customer admitted shocks from monitors, door knobs, desks, basically everything metallic in the environment. Customer pursued grounding mats in some areas and anti-static carpet in other areas. Misting the carpet with an anti-static fabric softner periodically also helped

3. re-design of ipphone handset - several years back there was a re-design of the telecaster handset to provide additional insulation from the internal components. This was ~3yrs ago from what I remember (cannot find the documentation at this moment, still looking). Are you using new 7960G phones or older phones?

How long has the installation been in place? Is this a new issue that just started or has it happened since day 1? How long ago was day1? What state is this install located in?

Please do open a TAC case and get your Account team onsite for a thorough investigation.

[adignan]

There are currently about 2000 IP phones placed for this install. The project is about 3 months old. We had not heard any complaints until last week. Complaints came from 2 specific users who said it has happend to them twice. Switch is a 3524, however the rack is not grounded. Phones should be the new 7960/7940G's. Maybe an old one slipped in. How could I tell if it is an old model? Customer is in Ohio.

[Wes Sisk]

Andrew, I am still searching for information on that, in the mean time can you pursue getting the rack and switch grounded to a valid earth ground? /Wes

[besselba]

The "shock" referred to is really electro static discharge or ESD. Simply put people generate static electricity and discharge when the charge finds a path. This is something most all of us have experienced at various times of our lives. Most of the time that path may be a doorknob, file cabinet, even another person. ESD occurs because of the lack of moisture in the environment and it's potential can be increased by what people ware. It is largely a wintertime phenomena. The best prevention of ESD involves keeping sufficient moisture in the air so that people don’t build up static electricity. Things like carpeting and what people ware also contribute. Wearing wool clothes, rubber soled shoes, etc.

The occurrence on Cisco phones is actually very low. Cisco IP Phones actually exceed any regulatory requirements for immunity. However form a practical standpoint higher immunity is desired to reduce the likelihood of ESD and improve user comfort level. As with any product there is a natural progression of improvements rolled into the manufacturing process. We are working toward a manufacturing improvement to improve ESD immunity in Cisco IP Phones