- Reaction score
- 157
I did some work today (added a new circuit) to a TT where earth electrode/Ra (bonding disconnected) was 198 Ohms. Bit close to limit where advice is to "investigate".
Interestingly the figure I got is precisely the same as that measured in 2010 by previous electrician, so it does appear to be fairly stable. Maybe grounds to leave it all alone since it's well below 500 (Property has 100mA RCD also on it's PV system) . Despite this I advised householder that probably good idea to re-check frequently, so I put 2 years on my EIC.
Were I to install a new electrode to improve the figure (another reason to upgrade might be that the electrode is a thin mild steel rod, not great looking, and with rust). - Then I believe it's OK (according to GN3) to simply measure Ra for the new one? (We have 30mA RCD's).
Soil type is mostly a sandy area. Alongside the electrode is an old (actually rather nicer) galvanized rod (now disconnected). I get exactly the same figure if I check this one also, which implies it might just be the soil (or they are both equally bad).
Is it the case that if I were to re-install, I could measure only Ra? - Or would I need to get my hands on an Earth Electrode Resistance Tester and do it properly?
Interestingly the figure I got is precisely the same as that measured in 2010 by previous electrician, so it does appear to be fairly stable. Maybe grounds to leave it all alone since it's well below 500 (Property has 100mA RCD also on it's PV system) . Despite this I advised householder that probably good idea to re-check frequently, so I put 2 years on my EIC.
Were I to install a new electrode to improve the figure (another reason to upgrade might be that the electrode is a thin mild steel rod, not great looking, and with rust). - Then I believe it's OK (according to GN3) to simply measure Ra for the new one? (We have 30mA RCD's).
Soil type is mostly a sandy area. Alongside the electrode is an old (actually rather nicer) galvanized rod (now disconnected). I get exactly the same figure if I check this one also, which implies it might just be the soil (or they are both equally bad).
Is it the case that if I were to re-install, I could measure only Ra? - Or would I need to get my hands on an Earth Electrode Resistance Tester and do it properly?