Humming on the CO lines 3

[ctvi]

The last two IP Offices I put in, the customer is complaining about humming on the line.
In one case, the lines were coming via Verizon FIOS.

Here is what I tried so far without good results:
1. "Automatic Balance Impedance Match."
2. I had Verizon come in to test the grounding.
3. I isolated the grounding to the system.
4. I replaced the cabinet.
5. Placed the system on a APC battery.

What do you recommend?

http://www.ctvi.com

 

[Westi]

IP phones?
not fun with analog lines, rarely works perfectly I have noticed and depending on how picky the customer is you will never have a satisfied customer.
SIP lines or PRI are the only real solution for that.
Digital phones?
No idea why it would do that, besides direct influence to the system you have ruled all out that you can.

Joe W.

FHandw., ACSS

insanity is just a state of mind

 

[busster]

Had this situation about a year ago. Finally replaced the ground. This resolved the issue.

 

[oldskoolindex]

same as,
had the same issue, replaced the ground and resolved bzzhmmmm.

 

[oldskoolindex]

try comming straight off the lines, see if you still get hum

 

[ctvi]

Can you specify how you replaced the ground? I did so too and it did not help.

I isolated the ground off the IP Office by converting the 3 prong to 2 prong connector to the wall and then ran a separate ground to the cabinet.

http://www.ctvi.com

 

[Westi]

don't go from a receptacle use a proper ground (cold water pipe) and see if that is solving your problem for testing purposes run a 4 pair cable to it and use all wires that saves you from running a ground wire and finding out 3 hours later that it doesn't change a thing.
Usually the receptacles are OK but you never know maybe this one is having the same problem that the system experiences with the hum.
thanks for the star ctvi always appreciated

Joe W.

FHandw., ACSS

insanity is just a state of mind

 

[ctvi]

I just installed another IP 500 - same humming issue. The first one is not corrected yet. I cannot convince my fellow techs that it is a grounding issue. How can I prove it scientifically?

http://www.ctvi.com