EV Charger reporting PEN Fault

[vwes59]

This is a baffling fault I've been fighting with for a couple of weeks now, so I wondered if another set of eyes will help.

I installed an EV Charger a few weeks back, and all went well for a while, then the client called me to say it wasn't charging randomly. Resetting it brought it back to life. When we interrogated the logs we were seeing a combination of Earth Fault and PEN Fault errors.

I retested everything right through and found no issues with regarding earthing, continuity and IR. I even did a full EICR on the house, with no issues found. (It needed it anyway, as the client had requested a new consumer unit).

Both the manufacturer and the DNO have been contacted and they acknowledge the fault but they are also at a loss as to what it is.

The only thing I noticed is the incoming voltage. Normally I see a reasonably stable voltage at a property, but in this case it was wobbling all over the place from 230V up to 247V. Unfortunately the DNO will not send out an engineer unless the voltage falls outside the range of 213V to 253V. But I was thinking, if the voltage is unstable and it suddenly dropped below 213V could it cause the EV Charger to throw a wobbly and misreport an Earth Fault ?

The only other thing, is to check for current leakage on the earth, but I can't remember how I can monitor that.

Oh finally the RCBO's are not tripping when this happens.

Any thoughts welcome.

 

[coatess]

This is a baffling fault I've been fighting with for a couple of weeks now, so I wondered if another set of eyes will help.

I installed an EV Charger a few weeks back, and all went well for a while, then the client called me to say it wasn't charging randomly. Resetting it brought it back to life. When we interrogated the logs we were seeing a combination of Earth Fault and PEN Fault errors.

I retested everything right through and found no issues with regarding earthing, continuity and IR. I even did a full EICR on the house, with no issues found. (It needed it anyway, as the client had requested a new consumer unit).

Both the manufacturer and the DNO have been contacted and they acknowledge the fault but they are also at a loss as to what it is.

The only thing I noticed is the incoming voltage. Normally I see a reasonably stable voltage at a property, but in this case it was wobbling all over the place from 230V up to 247V. Unfortunately the DNO will not send out an engineer unless the voltage falls outside the range of 213V to 253V. But I was thinking, if the voltage is unstable and it suddenly dropped below 213V could it cause the EV Charger to throw a wobbly and misreport an Earth Fault ?

The only other thing, is to check for current leakage on the earth, but I can't remember how I can monitor that.

Oh finally the RCBO's are not tripping when this happens.

Any thoughts welcome.

Hi, John Ward did a video on the effects of a broken PEN. What you have described sounds similar to the things shown on Johns' video.

 

[Simon47]

If you think about it, in the absence of a well installed earth rod for a reference, lost PEN detection can only be by inference if the supply voltage goes out of range. So supply voltage out of spec == infer lost PEN.

 

[James]

If you think about it, in the absence of a well installed earth rod for a reference, lost PEN detection can only be by inference if the supply voltage goes out of range. So supply voltage out of spec == infer lost PEN.

Agreed, loss of N further down the network can give wildly changeable voltages
If it is tied to earth, then that will go up and down too.