J
Jammin
Guest
Hi folks,
Tested the earth electrode on a TT system the other day and got a reading of 323 ohms. Normally I would install additional spikes to bring the value down, however the property is completely surrounded by concrete, and the customer will not consent to me digging anything up. so I removed the existing spike and installed a bigger one and got a reading of 282 ohms.
The spike I pulled out was in good condition but very dry as it appears not much moisture is penetrating the concrete. I can see no way of getting the reading below 200 with the restrictions the customer has implemented. I thought one possibility would be to get him to ask the DNO to upgrade him to a TNCS which would probably cost him, so he won't go for that!
Would I be right in thinking as the whole installation is protected by a 30ma RCD that because Ra divided by 0.03 allows for 1666 ohms for disconnection to occur it could be left as is. or do I walk away from it?
Tested the earth electrode on a TT system the other day and got a reading of 323 ohms. Normally I would install additional spikes to bring the value down, however the property is completely surrounded by concrete, and the customer will not consent to me digging anything up. so I removed the existing spike and installed a bigger one and got a reading of 282 ohms.
The spike I pulled out was in good condition but very dry as it appears not much moisture is penetrating the concrete. I can see no way of getting the reading below 200 with the restrictions the customer has implemented. I thought one possibility would be to get him to ask the DNO to upgrade him to a TNCS which would probably cost him, so he won't go for that!
Would I be right in thinking as the whole installation is protected by a 30ma RCD that because Ra divided by 0.03 allows for 1666 ohms for disconnection to occur it could be left as is. or do I walk away from it?