could anybody tell me what earthing-tns,tncs;tt,tnc or it means on a test sheet means recently had a report done and a bit confused at some ot the technical jargon used.
also what dose rated residual operating current in..ma
and operating time at in..ms stand for

julie, April 2010

I appreciate it may look confusing, the best way to look at it is like an MOT certificate - if there was anything which needed changing it would be mentioned, otherwise you just need to file it away with the schedules of tests and inspections until someone asks to see it.

Adam, April 2010

a big thanks for your quick reply thats what its says still not 100% what it all means but it good to have a reply

julie, April 2010

The type of earthing system refers to the way earthing is supplied to your property, which affects the maximum resistance permitted for the protective device to operate in the required time in the event of a fault.
An RCD (residual current device) will usually have a rating of 30mA (milliamps), and should operate in 40ms (milliseconds) at 5 times the rated value, ie 150mA (milliamps).

Adam, April 2010