Shock from kitchen sink via PV system,is that possible?

[contractor999]

Hi all,first post on this forum ,so be gentle with me.
Got called to a customer today,whose daughter got an apparent shock from the kitchen taps over the weekend.
We rewired kitchen ring main and lighting two years ago fed via wylex rcbo's all tested and certified.TNCS and 10mm bonding to gas and water.
Customer has had a PV system installed last November,not by us ,we dont install PV.
Apparently ,according to customer,Inverter started clicking quite loudly just before daughter received belt, and it showed orange fault light.Everything was switched off and then switched back on again and now all normal.
Have tested ring final circuit and lighting circuit RCBO's and all trip to original times.
I dont know anything about PV systems ,their earthing arrangements etc, but when customer rang PV install people they said there must have been an earthing problem on existing electrics.Well their isn't so what next?
Would welcome your thoughts on this.Thanks

 

[SolarCity]

Are you sure it isn't static?

I'd check on all earthing and bonding and take it from there. Any plastic piping been used? Supplementary bonding?

 

[Guitarist]

There is the chance that she built up some static , as solar says, then simply earthed herself out on the tap. Had the very same thing in an office block a few years ago... staff kept getting shocks off a metal door handle so I was called to sort it out. Turned out to be the synthetic carpet tiles as the women shuffled about in their man-made fibres. Everytime they opened a particular door...zap.

 

[SolarCity]

Being a TNCS system, you could have a dodgy neutral I suppose. First thing I would do is measure between the MET and the sink.

 

[contractor999]

Being a TNCS system, you could have a dodgy neutral I suppose. First thing I would do is measure between the MET and the sink.

Yes ,the first thing I suggested was static, and had arranged to go back with long wander lead to check from MET to sink,glad we are all thinking on the same lines.Thanks.
Any more suggestions would be gratefully received.

 

[Earthstore]

This is just a thought, where has the PV system been connected to?
Because if it is direct into the CU and on a shared RCD (common mistake by some pv companies) it could possibly have caused a fault, not sure how it could be through the tap though.

 

[SolarCity]

This is just a thought, where has the PV system been connected to?
Because if it is direct into the CU and on a shared RCD (common mistake by some pv companies) it could possibly have caused a fault, not sure how it could be through the tap though.

I don't think that would cause a fault as such - it would just stop the RCD from operating correctly.

 

[dansk]

Is there any electric UFH in the kitchen out of interest?

 

[contractor999]

No electric underfloor heating.

 

[dansk]

ok - its something ive come across before were a water leak caused the electric to track back to the sink - just a thought.

 

[moggy1968]

check the main earth is connected properly. If the solar is bonded back to the MET, but the main earth isn't connected then there is a possibility in the event of induction currents in the array or an earth fault, if it is earthed back to the MET, passing to it and then passing through the bonding to the pipework and taps.
I got called to a rental property once where a kitchen socket had worn through a cable (no grommet on the bac box). this then passed into the earthing through the supplementary bonding (connected to a back box). The main earth was loose so when the agents switched the taps on in the bathroom to show prospective tenants they got a bang.
Suprisngly the tenants didn't take the property!
but I have alsao been called out when it was static!!

 

[Gavin A]

as above - if this was the case, and the inverter was malfunctioning / shut down, it could be the capacitors discharging down the earth cable... maybe.

 

[MarkieSparkie]

Hi 999, You need answers to some basic questions before fault finding:- 1) What floor covering is there in the kitchen (if any)? 2) Was the flooring wet before the incident occurred (by accident or design)? 3) What footwear was the daughter wearing at the time (if any)? 4) Were the daughters hands wet at the time (from washing up or similar)? 5) Had the daughter come in from outside before the incident and had it been raining that day? 6) Has any plumbing work been done recently? 7) What was the time when the incident occurred. 8) Was it a sunny, overcast or wet day? These will get you started and you may well think of other questions to ask. The important point is gain all the information you can from the client and their daughter before getting the meter out, it will make you analysis of the situation so much easier. Best of luck, Mark.

 

[sedgy34]

i would assume thats a co-incidance or you could check there AC wiring see if there is anything unusual about it

 

[telectrix]

i think most daughters would get a shock from being in close proximity to a kitchen sink, due to realising that dirty dishes do not get magically washed, dried, and replaced in cupboards without human intervention.