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Posted By: 94astro Tell a youngster how to ground... - 03/15/07 11:48 AM
In a situation where there is no ground terminal, no drop ceiling to access copper pipes where would you ground to?? I've heard of people grounding to electrical outlets but I've never seen it or done it before... so under these circumstances where could I ground to without doing some major drilling to run a ground wire to a proper ground??
Posted By: justbill Re: Tell a youngster how to ground... - 03/15/07 11:54 AM
The only way you should ground to the electrical ground is at the panel, with the proper gauge of ground wire. What is it you're grounding? How far from the power panel? Plus all grounds should be tied together. So if you were to ground to a copper cold water pipe that pipe would have to be bonded to the power ground someplace also. You never want a difference in potential between your equipment ground and building, electric or earth grounds.
Posted By: EV607797 Re: Tell a youngster how to ground... - 03/15/07 11:58 AM
No, you shouldn't ground to an electrical outlet. That's not technically a building grounding electrode. You'll need to find some building steel, as in framing members like I-beams. Errico makes some beam clamps that will make this connection easy. Metal studs aren't considered to be building steel.
Posted By: 94astro Re: Tell a youngster how to ground... - 03/15/07 04:44 PM
What I'm installing is a phone system, NEC DSX80 which needs to be grounded or else you get a
very noticable humm on all CO's.

This is an old brick building that was pre-cabled by another company, hard lid ceilings everywhere and alot of concrete in the halls. The electrical panel is downstairs on the opposite side of the bldng.

I know these customers won't want to pay us to tear up things so I might have to leave it in the hands of the company that cabled the place.

Thanks for the info, I don't know what I-beams are but I'll look that up and maybe that will be the solution...
Posted By: hbiss Re: Tell a youngster how to ground... - 03/15/07 05:09 PM
I don't know what I-beams are...

I think we're in trouble.

For the solution to your "problem" click here. See that big wing nut binding post? Don't dare ask what its for...

-Hal
Posted By: EV607797 Re: Tell a youngster how to ground... - 03/15/07 05:31 PM
My suggestion would then be to look at Ditek's line of AC power surge supressors. Check this one out:

https://www.ditekcorp.com/product-details.asp?ProdKey=24

I have used them before in a pinch where a building ground was difficult to reach and they seemed to do OK. No failures, but I can't vouch for them. We may have just dodged a bullet. It does give you a "feel-good" place to run your system's ground to. There's still no substitute for a true building grounding electrode, as in a building frame member or copper water pipe.

As for the noise on CO lines, somebody is blowing "noise" at you. All systems must be able to operate in a normal environment without this concern or they wouldn't be FCC approved. The cabinet ground received from the third prong of the electrical plug is more than enough to provide a sufficient ground connection.
Posted By: justbill Re: Tell a youngster how to ground... - 03/15/07 06:08 PM
What Ed and Hal give as a reference wouldn't be my 1st choice for a ground, but sounds to me like it's your best option. That's just me, old school telecom #6 to a ground buss with all grounds common and no I'm not able to get it everytime. My second choice is the electric panel ground as it is usually a common ground. I also run #10 even though most systems say #12 I'm sure what's been suggested is plenty good for what you're doing.
Posted By: hbiss Re: Tell a youngster how to ground... - 03/15/07 06:24 PM
It wouldn't be my first choice for something like a protector ground but for most systems today that supplemental ground is just a redundant power cord ground. It serves no purpose other than a UL requirement in case the power cord gets yanked. You can actually cause more harm than good if you connect it to a ground other than where the power cord ground prong is connected to. So that Ditek unit is just what the doctor ordered.

I agree with Ed about your hum. If you are seeing this I would have an electrician check the power receptical for proper wiring and a ground. Just because a receptical has a ground hole doesn't mean that its connected to anything.

-Hal
Posted By: justbill Re: Tell a youngster how to ground... - 03/15/07 07:01 PM
You're right there Hal, I've seen the ground from the power cord strapped or under the external ground lug.
Posted By: 94astro Re: Tell a youngster how to ground... - 03/15/07 08:05 PM
That DITEK surge protector seems like a perfect solution for my case, thanks... But that humm on the Co's coming out of the NEC DSX80 is definately coming from the DSX, not the co's or improper ground (actually it could be a combo of both).

This system which has been out for less then a year will give you a humm if not grounded. We've installed about six of them and have heard that noise each time, all other times I was able to ground it fairly easy though. There have been posts in the NEC forum about this. Again, thank you guys...
Posted By: BillyBob Re: Tell a youngster how to ground... - 04/04/07 02:38 PM
94astro - The DSX80 has a known problem with the COIU-A trunk card which affects longitudinal balance and creates the humm. You definitely need to ground ALL three of the ground lugs inside the DSX cabinet, but that may not solve your problem.
If you are a certified dealer, you can contact tech support and they will send you a COIU-B card which will correct the humm. Also, you may have to upgrade the system to .28 software.

Bill
Posted By: 94astro Re: Tell a youngster how to ground... - 04/05/07 07:54 PM
For this install I did end up buying the DITEK unit (thanks fellas) and it did improve the humm a little, and fortunately zero complaints from the customer. I am running on the latest version .27.

A few months ago tech support sent us some DS1000 trunk cards to get rid of the humm and it didn't help at all, is the COIU-B card a new card made for the DSX?
Posted By: BillyBob Re: Tell a youngster how to ground... - 04/06/07 01:11 PM
Yes, the COIU-B is an improved version of the trunk card originally released for the DSX. I have a customer that had all the correct grounding, I tweeked all the gain settings but still had humm. Tech support sent be the COIU-B and, voila, humm gone!

Don't think for a minute that the COIU-B is a substitute for proper grounding as outlined by colleagues above. The DSX is still going through some tweeking and the COIU-B is one of those improvements. I have DSX systems in place with the COIU-A card and they also are properly grounded and don't have any problems with humm.

Bill
Posted By: 94astro Re: Tell a youngster how to ground... - 04/06/07 05:30 PM
Good to know...
Posted By: KLD Re: Tell a youngster how to ground... - 04/06/07 06:28 PM
Same here, BillyBob. No hum reported on any of mine with the "A" line cards. Surge, UPS, and GROUND !!!!!
Posted By: 94astro Re: Tell a youngster how to ground... - 04/06/07 08:00 PM
That's funny that you guys haven't experienced the humm, I've had it on every DSX I've touched (about 8), once it's grounded the humm is gone but there is still alot of sidetone.

They have gotten better with software upgrades, we really like the system, my boss likes it because it's inexpensive and I like it cuz it's easy to program and use with lots of features. Hopefully they've started shipping with the B trunk cards.
Posted By: ALLN1 Re: Tell a youngster how to ground... - 04/06/07 09:33 PM
I don't think that the B card are general release yet 94astro. Atleast not from my supplier. I believe the only way to get one is thru NEC tech support at this time.

As for the sidetone. First try changing the loop length. I personally have not had much luck with that helping. After that change the recieve gain. I have found -4 to be pretty normal around here. But play with it and see if it helps.

Brian
Posted By: 94astro Re: Tell a youngster how to ground... - 04/06/07 10:33 PM
I have played with the loop length and recieve gain, at one location we lowered the recieve gain too low and the voicemail wasn't hearing DTMF tones and was not transferring calls, and that install was auto attendant answer.

Right now we aren't getting any complaints anymore since all are at current software versions and grounded properly, the customers who are aware of the sidetone know that NEC is working on it and if we have to put the B trunk cards in then we will. It's been a pain, but again, we like the DSX.
Posted By: KLD Re: Tell a youngster how to ground... - 04/07/07 06:13 AM
Now that we have beaten the DSX hum to death, is there anything else we can do about the original post?

topic

94astro, it appears from your posts that the DITEK will do the trick. Anything else?
Posted By: Carl Navarro Re: Tell a youngster how to ground... - 07/04/07 09:55 AM
Content removed, it related to a typo in a spam message that was deleted
Posted By: Lesatel Re: Tell a youngster how to ground... - 07/04/07 09:57 AM
greetings!

I can respond any technical question that can have on these devices.

Happy 4 of July!

https://www.lesatel.com

welcome Lesatel. Thank you for offering to answer technical questions regarding these devices, however please note that SPAM is not allowed, so your other posts were removed. Thank you.
Altho this is an old, old, thread..... They only hum 'cause they "DON'T KNOW THE WORDS". smile John C. (Not Garand)
Posted By: KevCom Re: Tell a youngster how to ground... - 08/13/08 10:02 AM
Make sure if you are grounding to an I beam that you actually verify that it is an effective ground, also take the time to scrape the paint off of it for your connector. A bad ground is worse than no ground at all. For some reason in todays telecom industry very few people have the absolute importance of grounding in their mentality. It is not just an inconvenient hum on the line...its very dangerous (lightning etc) to have a poor or non-existent ground.
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