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#188359 - 08/01/09 11:56 PM Electronics and EGC
Niko Offline
Member

Registered: 08/17/06
Posts: 358
Loc: 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.
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#188360 - 08/02/09 12:03 AM Re: Electronics and EGC [Re: Niko]
sparkyinak Offline
Member

Registered: 07/08/07
Posts: 1296
Loc: Alaska
To ground it. smile They may have built in surge protection
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#188361 - 08/02/09 12:10 AM Re: Electronics and EGC [Re: sparkyinak]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9045
Loc: Estero,Fl,usa
I agree, I bet it is surge protection. Try to plug it in as close to the service as possible.
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#188362 - 08/02/09 12:28 AM Re: Electronics and EGC [Re: gfretwell]
Niko Offline
Member

Registered: 08/17/06
Posts: 358
Loc: 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.
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#188364 - 08/02/09 09:46 AM Re: Electronics and EGC [Re: Niko]
Texas_Ranger Offline
Member

Registered: 12/17/01
Posts: 2343
Loc: Vienna, Austria
I can see two reasons for an EGC on electronic equipment - surge protection and static discharge.

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#188366 - 08/02/09 11:45 AM Re: Electronics and EGC [Re: Niko]
westom Offline
New Member

Registered: 08/02/09
Posts: 3
Loc: 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.

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#188368 - 08/02/09 02:23 PM Re: Electronics and EGC [Re: westom]
EV607797 Offline
Member

Registered: 10/25/06
Posts: 756
Loc: 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.
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#188390 - 08/05/09 04:12 AM Re: Electronics and EGC [Re: EV607797]
pdh Offline
Member

Registered: 01/20/05
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.

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#188485 - 08/11/09 10:48 AM Re: Electronics and EGC [Re: pdh]
sabrown Offline
Member

Registered: 12/12/02
Posts: 297
Loc: 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.

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