Installing an earth rod - How do you do it

[Ramjam]

I have four systems in a row to install using transformerless inverters on PME supplies so I need to earth the array frame. I will be running a 10mm earth cable from the roof down to the ground floor in each case alongside the DC cables. When I get to the garage I'll mount the inverter alongside the consumer unit. I need to take the earth to a rod. so I drill a hole low down to the outside....

I need to fit an earth rod but there is a concrete path or a block set path, how would you do it and what equipment would you use and exactly how would you test it.

Previously I've only fitted TL inverters for arrays on agricultural sheds where earthing the array frame was easy. so I'm interested to hear your suggestion for smart domestic properties.

I was thinking....

core drill
whack in earth rod
test resistance to MET <200ohms in not extend the rod, whack in some more
Connect cable with a nice spring
Fit some sort of lid

????

 

[kamkam]

earth pit? is a plastic access housing for earth rods with key and lid (about 6" diameter and roughly 10'' deep)

 

[DurhamSparky]

RamJam / Kamkam........ Wind up....!!!!!

 

[billrag]

Installed one today.

 

[Ramjam]

RamJam / Kamkam........ Wind up....!!!!!

What ?????

 

[yellowvanman]

Make sure you know there are no drains or cables in vicinity
Drill hole through the concrete
Get Earth rod and put cover box over drilled hole
Hammer down earth rod - if its got a thread on top use a coupler and driving nut
If you use the 3/8" rod you can couple more than 1 rod together - if you have problems with soil conditions.
Clamp 10mm to rod
Test using earth loop impedance tester - taking L-N from a nearby socket - if your near the main CU even better.

If you're going to do a few then this may help:
Rapid Electronics - SDS-Max Earth driving rods

 

[kamkam]

Connect loop tester between line conductor at source and the earth electrode? the electrode should be disconnected from the met so that the test current passes though the rod alone otherwise you will be picking up parael paths from the properties main earth plus service pipes giving you a pointless earth reading of the rod? - or am i missing something? GN3 page 48 test method 2

 

[Matt_M]

The electrode shouldn't be connected to the met.

 

[Markc]

The electrode shouldn't be connected to the met.

It should be if installed on any other earthing arrangement other than TNCS.

As this is providing a escape path, for the want of another description, for DC fault current then I see no problem using the nearest socket to provide L - N for the tester. The CSA of the L conductor is lesser than the point of origin, higher resistance so the <200 ohms on the stake would be less than that recorded on the meter if measured from the origin.

As long as its under 200 ohms no problem either way really.