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Electrical Vehicle Charging Points - True earth on solid floor

Apostolos
Good afternoon.

The problem with EVC Points in a few words is that it introduces the PME (the MET in reality) voltage on the metallic car body. Then, if someone touches the car (under PME voltage) and stands on the ground touching the TRUE EARTH potential he will be introduced to a high voltage in case of an open PEN incidence. 

There are some gross guidlines ( https://www.electricvehiclechargepoint.com/ev-resources/earthing )that say

-If the EVC is outside then TT is needed (the person touches the true earth)

-If the EVC is inside and no charging happens on the outside then PME can be used (the person does not touch the true earth)

Then my question is:
WHAT IS THE POTENTIAL OF A CONRETE FLOOR IF THE EVC POINT IS INSIDE THE BUILDING????

Why do we assume that the concrete floor inside the building is on PME potential and so the EVC can be on PME?

If it is a metal building then I can see somehow that the concrete floor is in touch with the metal skeleton which is bonded to the MET so the concrete floor could be assumed to be on PME potential (correct me please if I am wrong)

If the building is concrete, how on earth this solid concrete floor is considered to be at PME potential????

 


Parents
  • 0
    It’s not unusual get an electric shock from a car with an internal combustion engine when you touch it due to static, indeed it can apparently damage hearing aids particularly those of children, according to some people healthy adults should feel the pain and take the shock to protect children and their hearing aids.


    The car charges up then discharges when touched by someone through their body and their shoes.


    So unless everyone is going to wear good quality wellies or the like I should not rely on footwear for protection from electric shocks from vehicles.


     Andy Betteridge
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  • 0
    It’s not unusual get an electric shock from a car with an internal combustion engine when you touch it due to static, indeed it can apparently damage hearing aids particularly those of children, according to some people healthy adults should feel the pain and take the shock to protect children and their hearing aids.


    The car charges up then discharges when touched by someone through their body and their shoes.


    So unless everyone is going to wear good quality wellies or the like I should not rely on footwear for protection from electric shocks from vehicles.


     Andy Betteridge
Children
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