17th advise

[ezekiel]

was at a job today (non electrical) and a firm had just carried out a pir and given there recomendations to client as:

main earth only 10mm needs upgrade to 16mm
no main bond to water needs 10mm
main bond to gas 6mm needs upgrade to 10mm

then as there was no rcd protection to sockets the main switch is to be replaced with a 30ma rcd is this correct or not?

 

[Spark123]

Depends really - what is the supply type? If it is TN-CS then the sizing needs to be run via the DNO. Then distance also plays a factor.
RCD on the whole CU is a bad idea and doesn't comply with regulation 314.

 

[Chri5]

Commercial installation, not the same as a domestic.

RCD protection on sockets isn't required (I think !!!).

 

[Spark123]

You'd need to read 411.3.3 to see if it applies, most instances RCD protection will be required.

 

[ezekiel]

its domestic and tncs assumed the earthing upgrade was ok but didnt agree with single rcd