Does a CPC require mechanical Protection

[Knobhead]

Reply to #14

No it doesn’t because the lines of magnetic flux in the conduit will be at 90° to the CPC current.

 

[Adam W]

Reply to #14

No it doesn’t because the lines of magnetic flux in the conduit will be at 90°to the CPC current.

That makes sense.

 

[Engineer54]

I think you'll find that this earth conductor is not a CPC (circuit protective conductor), but a bonding conductor linking the existing flats METs, making them in effect EMTs hopefully with a MET at the origin of the installation.


Now as both the conductor and the conduit are supposedly connected to these EMTs, any fault current flowing, will be carried by both the conductor and the conduit. At a disconnection time of a theoretical 0.4 sec, i doubt if a circulating current if any, would even have a chance to form.

 

[dodge26]

Sorry I asked, (only joking) brought up some intresting points. To be honest I just needed a get out as the spec is to link the MET'S and what is the cheapest way. Therefore as long as it's bigger than 4mm and clipped high enough that it can't be swung and nicked we will be fine.