R
RodMan50
Your welcome, be best you learnt the how tos and why fors
Shame you are not open to discussion :ack2:
Shame you are not open to discussion :ack2:
There is nothing in BS7671 or ESQCR prohibiting the exportation of a PME earth.
There are problems when the location the earth is being exported to has extraneous-condutive-parts, in sofar as an appropriately sized bonding conductor will be required.
Often this prohibits the exportation due to cost.
Are you really going to export a PME earth ?
Well that depends on what side of the fence you sit on
Plenty of export this and export that guides here, there and at the ESC etc
Shame really :ack2:
Are you really going to export a PME earth ?
Good Luck
How much experience have you with TNCS,PME and TT and exporting earths and the problems associated with it ?
I must admit, to being a Bitter person.
That Larger is just too bland for my liking.
To determine the CSA required for a CPC, you need to furnish the type and rating of the overcurrent protective device.
If for instance you intend using a 32A type B MCB, the time/current graphs in Appendix 3 of BS7671, indicates that the PEFC required to provide disconnection between 0.1 and 5s is only 160A.
Your calculated value of 800A will be more than sufficient to to allow the device to operate, and according to the adiabatic equation, will require a minimum CPC CSA of 0.44mm².
When using the adiabatic equation, what fault current do I use. The actual measured fault current ie 0.8kA in linked thread or the fault current required to trip the CPD which would be much lower
You would use your actual measured fault current if you have it available which would be 800A in this case. What the OCPD requires doesn't come into it.
2.1 Calculation in accordance with Regulation 543.1.3 Calculation uses one of two methods permitted by Regulation 543.1.3: [TABLE="class: listitem_table"] [TR] [TD="class: listitem"]• |
Reply to the thread, titled "CPC size help" which is posted in Electrical Wiring, Theories and Regulations on Electricians Forums.