High Ze

Magic figure for circuits under a 30mA rcd is 1666 Ohms.
Be very careful if you touch the clamp as it may be on the lead sheathing.
I would not be concerned about 1.03 in the greater scheme of things.
RS

 

I think it's fair to say that an earth electrode is exceedingly unlikely to reduce the impedance.

If the 1.03 Ohms is the result of a poor connection to the sheath then you should contact the network operator.

 

Agree with above. 1.03 ohms is unlikely to be of any concern to the DNO. They may or may not come out to it. You could try examining the main earth conductor connection on to the sheath but that's all you can do. If it was 10 ohms they might do something about it. You could recommend upgrade to a PME? Don't bother putting in an earth rod it will do jack ****.

 

Try a Ze test straight onto the sheath, that will tell you if it's a poor connection of the clamp or anywhere else whithin the installation.

 

The 1666 ohms (or more usually 1667 ohms) comes from Table 41.5 and is often taken out of context. In reality it won't ever be used. 200 ohms on a rod is considered unstable (See Note 2 of the table and the Reg referred to therein), and 100 ohms is considered as a safe stable limit. The 1667 ohms is used in the Reg 411.5.3 and is simply the mathematical result of the equation. 50/0.03=1667.

 

Quite correct Un, I did not elaborate on the basis that a sparks who is fitting a new consumer unit(whatever that now is defined as ) should be well aware of of the basic information regarding inspection and testing criteria, the latest regulations and on site guides. No disrespect to the OP.
RS

 

Concur!

 

If its a new board you have fitted you say, your RCD's will cover any times you cant get down on your Zs's

Notify the DNO and let them sort it, its down to them