low voltage to earth

[Daveh36]

Hi guys need help to stop me me from having no hair left. Been pulling it out for 2 days. Routine inspection RCD not tripping. But further checks show the voltage I'd too low. Old lead cable supply Ze 0.22 Only getting 1A fault current and voltage 193 volts to earth. Any ideas?

 

[Strima]

Voltage to neutral?

 

[Pete999]

Hi guys need help to stop me me from having no hair left. Been pulling it out for 2 days. Routine inspection RCD not tripping. But further checks show the voltage I'd too low. Old lead cable supply Ze 0.22 Only getting 1A fault current and voltage 193 volts to earth. Any ideas?

Is the voltage within the ranges specified

 

[Lucien Nunes]

Ze = 0.22 what? Ohms? Kilohms?
If it's 0.22 ohms, then the results don't match up which means one of the tests didn't work out. If it's kilohms then it might be correct, 230V / 220 ohms = approx 1A PEFC. Not very good earthing but not an error. The voltage reading depends on the effective input resistance of the tester... which test gave the 193V reading?

 

[Pete999]

Ze = 0.22 what? Ohms? Kilohms?
If it's 0.22 ohms, then the results don't match up which means one of the test didn't work out. If it's kilohms then it might be correct, 230V / 220 ohms = approx 1A PEFC. Not very good earthing but not an error. The voltage reading depends on the effective input resistance of the tester... which test gave the 193V reading?

Put the question better than I could Lucien, nice one

 

[pc1966]

If the supply really is down at 193V is it just possible the RCD electronics are unable to fire, but it would worry me and I suspect it is faulty. Basically I doubt anyone would make an RCD that was sooo... sensitive to low supply volts.

If you have an earth rod / TT setup then 220 ohms is just above what the reg say is "stable" but well below what is needed to trip most RCD. For 30mA / 100mA for sure, regs say 167 ohms for 300mA so touch voltage below 50V, but obviously 1A PFC would fire it if working!

But if the earth is using the lead sheath it ought to be a TN setup and then it is badly wrong!

Finally the low volts is a worry (if your meter is right, which it probably is). As asked above, what is the L-N volts? If they are 230V-ish then something is pulling the "earth" up noticeable. A fault on this load? Was it tested with all breakers open? Or a fault on someone else's system sharing this supply?

Any pictures, more info?

 

[Pretty Mouth]

I had a similar reading last week.

Simple job: disconnect a socket from a shed, remove old shed, build new shed, reconnect socket in new shed. A quick Zs test when finished to make sure all's well, but I'm getting >1999 ohms? Test voltage and I get ~240V L-N, ~210V L-E, and ~45V N-E. Turn off the breaker, test for dead, still getting ~45V N-E?

Okay, off to the board, Ze test >1999ohms. Open meter cupboard::