Ring or radial

[Farmelectrics]

Just done some small alterations to a training room it's a 4mm radial in dado trunking that was already there there is 7 pcs to be plugged into circuit I suggested making it into a ring but the engineer were working for says its ok I thought all pcs had to be on ring du to high integratity earthing

 

[Richard Burns]

It is not coming into contact with the earth leakage that is the main problem, although that is the effect we are trying to control, it is ensuring that the piece of equipment is continuously connected to the MET.
Because the suppression filters, SM power supplies, etc., generate a potential on the earth that can deliver over 10mA there is a risk of harm to someone touching any exposed conductive parts of the equipment if the equipment is not earthed, I know a lot of the desk IT kit is double insulated now, but there is a still a reasonable amount that is not and more in server rooms.
Also the lack of an earth will render the suppression useless as the leakage current is from a functional earth and without it the transients have nowhere to go.

 

[GLENNSPARK]

It is not coming into contact with the earth leakage that is the main problem, although that is the effect we are trying to control, it is ensuring that the piece of equipment is continuously connected to the MET.
Because the suppression filters, SM power supplies, etc., generate a potential on the earth that can deliver over 10mA there is a risk of harm to someone touching any exposed conductive parts of the equipment if the equipment is not earthed, I know a lot of the desk IT kit is double insulated now, but there is a still a reasonable amount that is not and more in server rooms.
Also the lack of an earth will render the suppression useless as the leakage current is from a functional earth and without it the transients have nowhere to go.

its effectively an earth screen....dumping stray...

 

[Engineer54]

Personally i wouldn't have more than 5 PC workstations on any one circuit!! Having RCD protection on PC/IT work station circuits, is just asking to loose any unsaved data, but it still seems all too common to do so!! lol!!

High integrity earthing is specified for a purpose, and something that the OP's Engineer should have been aware of, and suggested a dual/ringing of the CPC

 

[Farmelectrics]

But in these office I'm working in there is up to 16 pcs plugged in via a dual bus track under floor

 

[itselectric]

It's not been mentioned here, but I'm almost sure from memory that the 4mm cpc has to follow the same route as the circuit cable and to be clipped with it.

 

[Engineer54]

But in these office I'm working in there is up to 16 pcs plugged in via a dual bus track under floor

So does that make it right then??