Grounding networking devices?

[gef]

Hi,

TL;DR: Is it really necessary to ground a patchpanel or, if building a networking rack, the entire rack and why?

 

I recently discovered that the supposed "telephone jacks" dotted around our house are actually wired with cat.6a cabling, all arriving in the attic and most sitting there unterminated.

I would like to hook them all up to a switch, as to take advantage of our new fiber connection without having to always rely on WiFi. Since I have never done anything involving putting together hardware I spent quite some time researching what ist needed, and stumbled upon patch panels. Thus my idea is to terminate all these (8) wires into a patch panel in the attic and then use short patch cables to hook them up to a switch and maybe put both in a small 6U rack as a means of keeping things tidy.

But during my research I have stumbled upon various internet forums (all in German, sorry) claiming that I need to ground the rack and all components within, lest I risk not only damaging my components but having life-threatening 240V on the outside.

I can't help but wonder why this is supposed to be necessary though, because was under the impression, that all components are grounded via their respective plugs? I have also never noticed anybody saying this during home network upgrade videos (eg. here or here).

But even if I didn't use the rack (this is after all going into the attic that serves only as a storage space), I noticed that even patch panels not designed for rackmounting seem to have some sort of grounding cable (see for example here). Is it necessary to connect that to anything in this sort of home network? And if it is - why? If I'd be terminating the cables into rj-45 and plugging them directly into the switch, I wouldn't be grounding anything either. So what is the difference?

Thanks in advance!

[Windows7ge]

If the devices you put in the rack have ground plugs they'll pop the breaker if live ever shorts to ground.

 

Where you might like to make your own ground is when a device that take 240AC in doesn't have a ground. If that shorted to the case that could get shorted to the rack and suddenly you have a rack that's live at mains voltage.

 

Luckily most basic small port network switches run off low voltage DC and most high end networking equipment is grounded. Unless you're looking to protect from an external force like a lightning strike there's no overwhelming reason to do this.

[TetraSky]

If the external chassis is made of metal, it should be grounded as per the electricity code of most/any sane country.

The only instances where it doesn't really matter if there is a ground or not, is if the chassis of the device is made of an insulating material, like plastic.

 

Metal conducts electricity. Many appliances use the metal chassis as sort of "ground" for the components inside of it and you then need to connect the chassis to the actual ground, for without it, the charges that would normally be dissipating through ground, will just accumulate in the chassis and cause you to get shocked if you touched it/fry your devices or forcefully power them off if they have protection built-in for such cases.

 

29 minutes ago, gef said:

because was under the impression, that all components are grounded via their respective plugs?

This is correct, yes. Some might not. If yours do, don't worry about it.

Some may just have the live and neutral prongs/wires without the additional ground.

This typically means that it use your service panel (electrical box for the house) as the ground via the Neutral, instead of a dedicated wire for ground. Not ideal.

Ground wire typically only carry voltage in case of a fault. Like say, a rat eats up your washing machine's wires, causing them to touch the metal chassis. Typically, the voltage going through the chassis would be sent to the ground and trip the breaker. Without the ground, it will just accumulate in the chassis and if you touch it, you become the ground path and get shocked.

[gef]

Ok, thanks for your responses.

28 minutes ago, Windows7ge said:

Luckily most basic small port network switches run off low voltage DC and most high end networking equipment is grounded. Unless you're looking to protect from an external force like a lightning strike there's no overwhelming reason to do this.

 

26 minutes ago, TetraSky said:

If the external chassis is made of metal, it should be grounded as per the electricity code of most/any sane country.

So what I'm gathering is that I don't really have to worry about grounding, is that correct?

40 minutes ago, TetraSky said:

Metal conducts electricity. Many appliances use the metal chassis as sort of "ground" for the components inside of it and you then need to connect the chassis to the actual ground, for without it, the charges that would normally be dissipating through ground, will just accumulate in the chassis and cause you to get shocked if you touched it/fry your devices or forcefully power them off if they have protection built-in for such cases.

I am thinking of getting the TP-Link TL-SG1016D as a switch, as to have a bit of room for expansion past the 8 wall wires and what I'm gathering from the manual (page 8, and this guide) is that I don't have to worry, right?

 

I still can't help wondering though, why the patch panel (e.g. this one or this one I'm thinking about) seems to have a wire intended to be some kind of ground. It's passive, so it doesn't even have ta ability to cary any kind of voltage, right?

Thanks for your help!

[Windows7ge]

3 minutes ago, gef said:

So what I'm gathering is that I don't really have to worry about grounding, is that correct?

Local laws & regulations aside. If they don't say you have to have one I wouldn't worry about it. Most/all of your equipment should have dedicated grounds.

 

7 minutes ago, gef said:

I am thinking of getting the TP-Link TL-SG1016D as a switch, as to have a bit of room for expansion past the 8 wall wires and what I'm gathering from the manual (page 8, and this guide) is that I don't have to worry, right?

 

I still can't help wondering though, why the patch panel (e.g. this one or this one I'm thinking about) seems to have a wire intended to be some kind of ground. It's passive, so it doesn't even have ta ability to cary any kind of voltage, right?

Thanks for your help!

I have a switch very similar to that. It comes with it's own ground.

 

I think this is where we come back to lightning strikes or electrical faults. You don't want high voltage AC or other electrical discharges going down low voltage DC cables to sensitive networking equipment so they give you the option to tie the chassis to ground. The switch you're looking at has an anchor on the back where you could tie that patch panel to ground. If this concerns you it won't hurt anything to use it. It'd be proper to anyhow.

[TetraSky]

16 minutes ago, gef said:

I am thinking of getting the TP-Link TL-SG1016D as a switch, as to have a bit of room for expansion past the 8 wall wires and what I'm gathering from the manual (page 8, and this guide) is that I don't have to worry, right?

Correct, it has a built-in ground to the wall.
You can even see it on videos when he pulls out the power plug. Three prongs.

 

 

16 minutes ago, gef said:

I still can't help wondering though, why the patch panel (e.g. this one or this one I'm thinking about) seems to have a wire intended to be some kind of ground. It's passive, so it doesn't even have ta ability to cary any kind of voltage, right?

Actually, they are not exactly truly "passive".

These cables can in fact carry some voltage through them in the day to day, but it's usually between 0V and +- 2.5V. Very low, but still something.

 

Not to mention, Power over Ethernet is a thing if you have the appropriate hardware and cables.

https://en.wikipedia.org/wiki/Power_over_Ethernet

 

Now I don't know if the particular devices you're showing supports that, but regardless of whether or not it does, typically that ground is for lightning strikes and not so much for the ethernet switch itself.

If you're getting the TP-link switch, don't worry about any of this.

[gef]

5 minutes ago, Windows7ge said:

The switch you're looking at has an anchor on the back where you could tie that patch panel to ground. If this concerns you it won't hurt anything to use it. It'd be proper to anyhow.

Ok, I didn't realise I could just ground the patch panel via the switch, but of course it makes sense. Thanks a lot to both of you!