3 phase stray voltage

[jason.h]

i recently had a problem on the farm-came into the farm house and touched the dishwasher door to receive a mild shock!-turned off the power but pretty much everything metal in the house was still live.The same goes for the farm - shed steel,feed barriers,etc.etc. all live. The problem was traced to a corroded connection in the neutral junction box. My question is ,apart from a new junction box and fresh ends on the neutral cables-how can i prevent this from happening again??

 

[(*steve*)]

Can you protect it further from the elements? My initial assumption is that this is what caused the corrosion.

Do you have earth bonded to neutral?

My suspicion is that you also have a poor earth connection and that the neutral fault essentially caused your earth to float to some proportion of mains voltage.

Sounds potentially nasty.

Please note that I'm not a sparkie, that's who I would be directing these questions to.

 

[KrisBlueNZ]

I agree with Steve. I would get your system checked out by a registered electrician, if you haven't already done so, and set a yearly alarm to remind you to do a visual inspection of your distribution board, earth stake, and anything else the electrician recommends.

I would suggest installing an ELCB (aka RCD, GFCI etc) but I'd imagine it would just nuisance trip all the time with those heavy loads. But an electrician with experience of your type of installation is the best person to advise you.

 

[duke37]

You need to get it sorted by a competant electrician. I know of a case in Shropshire where most earthed devices were at 80V. It stopped the sheep shearing. The neutral and earth were bonded correctly in a PME (phase multiple earth) system but here there was only one earth. The problem was a leaky 11kV supply transformer - not very nice.

 

[jason.h]

thanks for the replies,im not sure if the earth is bonded to the neutral,i think not.the system was installed a fair time ago and nature has obviously taken its course on the components, i will take the advice and get sparkie in to renew whats needed