IEC 60364 Table 48A

Before the RCD was as reliable as it is today,  the EEB part was taken more rigorously.

From

15^th Edition Regulations (1981) 

Regulation 413.7 required metal parts within the equipotential zone to be supplementary bonded to maintain the equipotential zone, where those parts:

1. Are extraneous-conductive-parts, and

• Are simultaneously accessible with exposed-conductive-parts or other extraneous-conductive-parts, and

• Are not electrically connected to the main equipotential bonding by permanent and reliable metal-to-metal joints of negligible impedance.

Now the keen can read that so you need to bond the door handle to the toothbrush holder in the bathroom  if less than say 6 ft apart, and some folk did rather run away with that sort of thing, and a lot a green and yellow wire was sold and installed in places that confuse the younger electricians, bonding taps to metal window frames and so on.

This pic is copied from (another post) and shows the "best practice" of the time.

Being the UK that means almost no-one did it completely correctly.

Had it been Germany it would have been like this in every house, had it been somewhere sunnier  no-one would have bothered at all. What you find in reality is sort of in between those extremes.


Note all those dotted lines are supposed to be equipotential bonds.  (Oddly except the pull cord light switch - perhaps they assumed that the string had broken and been replaced by an offcut of earth wire... quite possible in the 1970s I suppose.)

Note this a bit of an artists impression, and not all older houses had massive kitchens and bathrooms and no electricity in sleeping accommodation or living rooms, and although not shown, most post war buildings had toilets inside, & in others  the outside one would have been upgraded to electricity for lighting at least ... ?


Mike.


EEBADS at peak enthusiasm..

Before the RCD was as reliable as it is today,  the EEB part was taken more rigorously.

From

15^th Edition Regulations (1981) 

Regulation 413.7 required metal parts within the equipotential zone to be supplementary bonded to maintain the equipotential zone, where those parts:

1. Are extraneous-conductive-parts, and

• Are simultaneously accessible with exposed-conductive-parts or other extraneous-conductive-parts, and

• Are not electrically connected to the main equipotential bonding by permanent and reliable metal-to-metal joints of negligible impedance.

Now the keen can read that so you need to bond the door handle to the toothbrush holder in the bathroom  if less than say 6 ft apart, and some folk did rather run away with that sort of thing, and a lot a green and yellow wire was sold and installed in places that confuse the younger electricians, bonding taps to metal window frames and so on.

This pic is copied from (another post) and shows the "best practice" of the time.

Being the UK that means almost no-one did it completely correctly.

Had it been Germany it would have been like this in every house, had it been somewhere sunnier  no-one would have bothered at all. What you find in reality is sort of in between those extremes.


Note all those dotted lines are supposed to be equipotential bonds.  (Oddly except the pull cord light switch - perhaps they assumed that the string had broken and been replaced by an offcut of earth wire... quite possible in the 1970s I suppose.)

Note this a bit of an artists impression, and not all older houses had massive kitchens and bathrooms and no electricity in sleeping accommodation or living rooms, and although not shown, most post war buildings had toilets inside, & in others  the outside one would have been upgraded to electricity for lighting at least ... ?


Mike.


EEBADS at peak enthusiasm..