Power and ground issue?

[thattekguy]

I have an 11 mini rls 25.30 that has been working fine for the longest time. Last week all of a sudden they could not make or recieve calls.All calls come in on copper trunks and Auto terminate to voicemail.When this was reported voicemail was down as well, it did not show any VP cards in the system, so I reloaded the switch and they came back and mail came back up, but still no trunks. Seems easy enough, bad ground right, but the ground measured at .03 ohm's, and is going straight to a rod in the basement floor.The circuits themselves have dial tone at the Dmarc and can call in and out on them with no problem at the Dmarc.We did have a problem with the PBX being plugged into a power strip, which was plugged into a UPS, I bypassed the power strip and the ups and went straight into the isolated outlet.The AT&T tech reported seeing a Ring Ground on the lines, this was resolved after removing the power strip, I thought that would be it but no good.We have tried the maint set and can not get dial tone,dialed the ACOD and get a loud scream on the line.When dialing different numbers going into the switch gives me different responses, two numbers when I dial them, knock me out of my remote connection as soon as the call hits the switch..all of a sudden my modem connection gets dropped. Another number will ring and answer every time on the same TN with no problem. I also switched out trunk cards and switched card slots from slot 9 to slot 2, which is a different chassis.I took off the ground and put a new ground from a screw on the faceplate of an outlet and still nothing.Also when you dial in and dial out the trunks go into a lockout.We tried different outlets in the room as well.I am sending a new SSC card to the site to see if that clears anything up. I am also going to measure the voltage on the circuits today to see what I have coming in, even though AT&T says theyre fine. Any ideas will be greatly appreciated, this has been going on for a few days now.

 

[telebub]

My rule of thumb is to run the #6 frame ground back to the power panel that is feeding power to the UPS/equipment. This way the 3rd wire ground in the outlet and the frame ground are parallel back to the same ground source.


War Eagle!!

 

[thattekguy]

Yes XO from the panel would be the best but I don't think it is a choice. I did ask for that but I'm still waiting for a response, this site is in California and I'm in NY working remotely with techs, so it's that much harder to accomplish things.I also had the circuits measured today and they are all in a good range.My next step is to replace the SSC card and try for the new ground. Did I mention loop start works fine thru the pbx.

 

[Phnman]

Post your Trunk Programming so we can see if they are programmed correctly in your PBX. One other thing are you sure the Trunks from TELCO are in fact GRD Start. From your description of the problem it almost sounds as if your telco is LOOP Start.

 

[thattekguy]

ive been at this for a couple of days,thanks for the idea but that was obviously the first thing i checked,they are ground start from telco. The programming is ok it is set for GRD. i will post all programming though my next post. thanks any other ideas? i think ive exhausted everything except for new ssc card or new chassis all together.

 

[thattekguy]

Just an update.
I had the chassis disconnected from each other and moved the trunk card into a slot in the main chassis, slot 2, and the calls work.