Cat6a cabinet earthing

[Nellkin]

Hi all.

I am replacing some cat5e cable with cat6a shielded in a large building. I have noticed the cabinets are NOT earthed and the electrical maintenance team have said they can provide this but have asked can it come from the local electrical board OR the MET.

Do all cabs need to be earthed back to to either the local or MET?

 

[James]

they dont need to be earthed from an electrical regulations standpoint.
all cables entering them will be double insulated and any equipment installed will either have its own earth (cpc) from its plug or be a class 2 device that requires no earth.

there may be some benefit in providing a "clean earth" in some circumstances but your network engineers should be able to tell you if they feel it is necessary.

 

[pc1966]

Generally speaking you do not want a mixture of earthing systems in any installation, I think there might be a wiring regulation prohibiting that.

For data cables going between locations it presents a problem as normally you want to link both systems 0v references together but then you have the problem that under fault conditions those data cables are unable to cope with the sorts of currents involved and can be damaged or even become a fire risk.

If they are all in the same building, then I would expect each area to be earthed to the local DB, and those in turn back to the main supply point's means of earthing, which should be OK. But wise to check. If it is different building you have a problem.

Really if you are running Ethernet it should be less than 100m anyway, and if in doubt for medium/long/site crossing distances you ought to be looking at fibre optics instead. Cost is not much these days, excellent safety/noise immunity, and often they will support future speed upgrades to 10G in single mode fibre (limited distances for multimode).

 

[pc1966]

I have noticed the cabinets are NOT earthed

Do you mean the likes of 19" racks?

 

[Nellkin]

Generally speaking you do not want a mixture of earthing systems in any installation, I think there might be a wiring regulation prohibiting that.

For data cables going between locations it presents a problem as normally you want to link both systems 0v references together but then you have the problem that under fault conditions those data cables are unable to cope with the sorts of currents involved and can be damaged or even become a fire risk.

If they are all in the same building, then I would expect each area to be earthed to the local DB, and those in turn back to the main supply point's means of earthing, which should be OK. But wise to check. If it is different building you have a problem.

Really if you are running Ethernet it should be less than 100m anyway, and if in doubt for medium/long/site crossing distances you ought to be looking at fibre optics instead. Cost is not much these days, excellent safety/noise immunity, and often they will support future speed upgrades to 10G in single mode fibre (limited distances for multimode).

Its all in the same building just opposite ends.
Fibre will be run but cat6 and cat6a also.
As its same building i will ask if local boards are on same earth system to be sure. If they are no need to trudge back to MTE and they will then have the asbestos doding to do.
Thx for the input