ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
twh 10
Recent Posts
Correct rotation, wrong sequence
by Potseal. 05/27/17 12:15 AM
Dryer, Range grounding from "Main" panel
by sparkync. 05/25/17 05:49 PM
210.70 / Wall Switch / When adopted?
by gfretwell. 05/24/17 09:18 PM
Any UL 508 experts out there?
by sparkyinak. 05/23/17 11:04 PM
Heat pump conundrum
by sparkyinak. 05/21/17 08:49 PM
New in the Gallery:
SE cable question
Popular Topics(Views)
236,871 Are you busy
171,872 Re: Forum
164,781 Need opinion
Who's Online Now
0 registered members (), 66 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
#188359 - 08/02/09 02:56 AM Electronics and EGC  
Niko  Offline
Member
Joined: Aug 2006
Posts: 356
Campbell, CA
AT&T has a new product and they insist that the router/modem be connected to a grounded outlet. I know the grounding and why we need it in good detail. Besides the obvious, why do electronics need the EGC in order to operate properly?

I have asked different AT&T techs as to why the ground is important for their electronics but haven't been able to get a good answer.

Thank you.


Be kind to your neighbor, he knows where you live


Work Gear for Electricians and the Trades

#188360 - 08/02/09 03:03 AM Re: Electronics and EGC [Re: Niko]  
sparkyinak  Offline
Member
Joined: Jul 2007
Posts: 1,322
Alaska
To ground it. smile They may have built in surge protection


"Live Awesome!" - Kevin Carosa

#188361 - 08/02/09 03:10 AM Re: Electronics and EGC [Re: sparkyinak]  
gfretwell  Offline


Member
Joined: Jul 2004
Posts: 9,080
Estero,Fl,usa
I agree, I bet it is surge protection. Try to plug it in as close to the service as possible.


Greg Fretwell

#188362 - 08/02/09 03:28 AM Re: Electronics and EGC [Re: gfretwell]  
Niko  Offline
Member
Joined: Aug 2006
Posts: 356
Campbell, CA
well in that case I assume in an apartment complex without an egc a GFCI will do us any good for the surge protection.

time to cut sheetrock to get EGC installed from the panel.


Be kind to your neighbor, he knows where you live


#188364 - 08/02/09 12:46 PM Re: Electronics and EGC [Re: Niko]  
Texas_Ranger  Offline
Member
Joined: Dec 2001
Posts: 2,396
Vienna, Austria
I can see two reasons for an EGC on electronic equipment - surge protection and static discharge.


#188366 - 08/02/09 02:45 PM Re: Electronics and EGC [Re: Niko]  
westom  Offline
New Member
Joined: Aug 2009
Posts: 3
us
Originally Posted by Niko
AT&T has a new product and they insist that the router/modem be connected to a grounded outlet. I know the grounding and why we need it in good detail. Besides the obvious, why do electronics need the EGC in order to operate properly?

Ever touch a refrigerator that is powered but not safety grounded? Rub a finger on the metal to feel a tingle? That 60 volts is leakage from 120 volts. Leakage currents that may be microamps. Without a safety ground, those microamps create 60 volts.

Same is often true of electronics. Besides the obvious - safety ground - those leakage currents must be harmlessly conducted. That 60 volts has a potential of creating other problems - operational or reliability.

That safety ground does nothing for surge protection. Wires that are too long, too many sharp bends, splices, bundled with other non-grounding wires, etc cannot properly conduct surge currents. Safety ground has problems such as high impedance which is why that wire is a safety ground (or equipment ground) and not earth ground.


#188368 - 08/02/09 05:23 PM Re: Electronics and EGC [Re: westom]  
EV607797  Offline
Member
Joined: Oct 2006
Posts: 745
Fredericksburg, VA, USA
It is true that the ground requirement is for static discharge on most telecommunications equipment. You will rarely see any of this equipment installed today that actually requires a ground to operate.

There is one exception: If the device is providing ground start trunks, then yes, a ground is absolutely necessary in order to have a point of reference. The trunks won't work if this reference ground isn't present. People don't usually order ground start trunks anymore, but lots of existing hotels use them.


---Ed---

"But the guy at Home Depot said it would work."

#188390 - 08/05/09 07:12 AM Re: Electronics and EGC [Re: EV607797]  
pdh  Offline
Member
Joined: Jan 2005
Posts: 354
Many device will operate fine without a ground. But the manufacturer won't accept any liability unless their instructions are followed.

The EGC does very little for surge protection. Surge protection at point of use is more about equalizing the voltage changes so components inside do not get voltage differences beyond their design limits. Devices like routers that are connected to wired networks need building entrance protection to prevent damage from surges. Point of use protection primarily helps groups of interconnected devices only when all the devices in the group share a common protector.

Proper grounding can improve signal quality. Power line hum can disrupt the data signals. The device may be using the EGC as a reference voltage for the networking interface.

It would be best to supply the unit with specified grounding connection, regardless of the benefit or cause, just because that's what is specified.


#188485 - 08/11/09 01:48 PM Re: Electronics and EGC [Re: pdh]  
sabrown  Offline
Member
Joined: Dec 2002
Posts: 302
Ogden, Utah, USA
To add to "pdh's" comments, proper grounding to a metal case also provides a shield against the grounded device emitting radio frequencies that may affect the operation of other devices. This allows items to meet FCC requirements.



Member Spotlight
SafetyWired
SafetyWired
Pa, USA
Posts: 44
Joined: July 2013
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.018s Queries: 15 (0.003s) Memory: 0.8028 MB (Peak: 0.9743 MB) Zlib enabled. Server Time: 2017-05-27 11:52:56 UTC