Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Electrical phenomenon

Kinda makes you wonder how did they earth Edinburgh Castle..

Makes sense when you consider any current leakage through your body will be with respect to the ground you are standing on not the house.

Furse could well have been involved - they did a lot of work on protecting our radio transmitting sites for lightning protection. We carried out a lot of our own work using brazing sets and Cadweld, which could get a little interesting at times... and of course the odd setting fire to the Machair incidents kept us amused..

Earls Hill was a bugger of a site near Stirling with a 600' mast and after a big strike you could smell the ozone of the corona for hours in the building.

Richard, thanks for the heads up on Furse.. Quite some time back I was required to attend a then new tracking station on South Uist built on the top of a mountain. Apparently the elect engnr told me it cost more to earth than wire the building. I was told they had to dig up the peat bog at the bottom of the mountain, lay down acres of copper mat, and lay the peat back down on top..?

My house sits on mostly rock with perhaps a meter of soil in places, thus earth rods don`t cut it.. When I built the most recent extension I used plastic for the water pipe, part of the mains supply it plastic too, dug down and found the old out of use 2" steel water supply pipe, cleaned it up up and connected to that in order to get some sort of earth reading and to pass the electrical safety test regs for my then new self-build.

Prior to that I used to get an occasional tingle from the conduit mounted metal light switch in the garage, when the paint wore off the switch, any time I was spraying paint I would give the old switch another coating of paint... Yeah that garage is long gone, saved me rewiring the place, I built another home extension over it`s foundations..Madness...Duh !!!

If the weather south has been anywhere near as dry as it has been for weeks up here in NE Scotland it might be worth treating your earth rod to a couple of watering can's full of water .... they're less efficient in dry soil.

K

Out of curiosity I contacted CTEK re the buzzing or tingleling when touching the car with the charger attached. Worth posting their reply should anybody have concerns.

"This is specially the case when:
• The air and vehicle tires are dry, typically indoor a warm garage or in a dry season of the year with a very low humidity. The vehicle is then well electrically insulated from ground potential.
• Electrical equipment as for example a battery charger is connected to the vehicle.
• A person touching an electrically conductive part of the vehicle and at the same time touches a part that is well connected to the ground potential as for example an electric lift device in a workshop.

This small leakage current is normal and derived from the EMI filters inside the battery charger. These filters are necessary to keep the radio interferences from the unit to a minimum.

Normally the leakage current will drain down to ground through the dirt and moisture on tire or other surfaces and the residual current is not detectable by touch.

The leakage current of all our mains connected chargers are certified by a third party safety institute to verify that the leakage current is below limits and harmless to human body.

How to avoid this?
To minimize the discomfort in these situations you may add an electrical connection between the vehicle chassis and ground by using a single jumper start cable. Alternatively use semi conductive lift pads between vehicle and lift/jack support. "

Thanks for posting CTEK's response Roger

When it's dry and warm I get a static discharge from our Polo every time I get out and touch the door to close it. Every time. No CTEK involved.

Dave you really need to stop wearing that synthetic underwear...

Or always wear wellingtons.........