Simultaneous contact assessment (EV charging)

I watch you tube with the efixx report, and they brought up the on street charging issue, and the problem to ensure different earthing methods used with street furniture does not create a danger.

This seems to be a problem, however we look at earth rod covers and are very different in to how close to the rod a pedestrian can get. In the main when in the drive or street we have some cover be it brick sets or slabs which mean we are not walking on soil next to the earth rod, and from a building we should be looking at least 2 meters before we park a caravan or motor caravan when in use so the IET picture should not exist as we should not be able to part the car so close to a building.

However how can one test until there is a fault condition. My local lamp post does not have a sticker saying TN-C-S or TT on it, one would hope not TN-C-S, but can't see how anyone can test some one else's street furniture to find out how earthed.

If I look at where I work, the metal framed building started life as new business start up units, so it has at least 4 supplies, since all in the same metal framed building they should not be TN-C-S, however I have a feeling they are. The EV charging point is less than a meter from the building, I am told TT, however clearly the metal cladding and charge point can be both touched together. Not really worried, as it is connected to 8 mile of railway track, so unlikely any dangerous voltages will be their even with loss of PEN.

But best will in the world, can't see until a fault happens, how one would test? It would require the DNO to put labels on all their supplies saying what earthing system is being used put where all can view, having to open some cover to see earth system used would not work.

And all underground services would need to be isolated from any TN-C-S or PME supply. The only way on street charging can be 100% safe is to ban TN-C-S/PME supplies.

Interested to hear what others think.

 

Page 24 is interesting, it seems to require a 2 meter space between the parking bay and any street furniture which may have electric to it.

That is likely to be a problem with the provision of gullies as typically each house is on a different phase, so parking space recommended is 2.6 x 5 meters, so house frontage would need to be 9 meters long. In the main people with that length frontage do not need on street parking.

I like @Comlec will not likely get an electric car, and even if I did, I have rear of property parking which can take 4 cars, so would not need to charge a car where the public, even the postman and milkman will have access.

However I will likely at some point walk past a car on charge, and will not be wearing full PPE when walking past it. To look at the installation on private property where one knows the supply type, and if the items are class I or class II, and have plans for underground services is fair enough. But in the street it is very different. I have no idea if water pipes are iron or plastic, or where the services run.

I can use my loop impedance tester and have a good idea if the supply is TN or TT, but to work out if TN-S or TN-C-S can't do that, and can't use my loop tester on the councils lamp post, so not really a clue as to what street furniture earthing system is.

I know where I work TN-C-S is not allowed, for multi supplies in a steel frame building, but I am reasonable sure it is TN-C-S, but can't prove it. And the EV charging point is not 2 meters from the building.