mapj1:

It was called 48A in the older withdrawn versions, then in 2001 it became
Table 41C (48A) – Maximum disconnecting times in the then new  Electrical installations of buildings Part 4-41:

in the 2005 version it became Table 41.1 – Maximum disconnection times

As far as I know the numbers have not changed at all for years, and we are now in the 2017 edition.

The figures in the UK regs are a direct copy without the bits for 120V land.

From what I gather, the disconnection times were faster in 48A for certain locations by a factor of half.

mapj1:

Interesting I was not aware of that. Then we/you  need to track down a pre 2000 version of the standard.


Mike.

 

I can't find the 2000s version, at least not for free. Someone else will need to.

mapj1:

It was called 48A in the older withdrawn versions of 60364-4-41 , then in 2001 it became
Table 41C (48A) – Maximum disconnecting times in the then new  Electrical installations of buildings Part 4-41:

in the 2005 version it became Table 41.1 – Maximum disconnection times

As far as I know the numbers have not changed at all for years, and we are now in the 2017 edition.

The figures in the UK regs are a direct copy without the bits for 120V land.

Hang on ... in 2001 edition, Table 41C (48A) is NOT an equivalent of what we have now in Table 41.1. It only applied in cases where the relevant part 7 (IEC 60364-7-7xx) reduced the maximum permissible touch voltage via equipotential bonding to 25 V AC or 60 V DC. See C|Lauses in 413.2 of the 2001 version.


For TN systems under usual conditions, see Table 41A and 41B of that standard ... which became what we now have as Table 41.1.

gkenyon:

mapj1:

It was called 48A in the older withdrawn versions of 60364-4-41 , then in 2001 it became
Table 41C (48A) – Maximum disconnecting times in the then new  Electrical installations of buildings Part 4-41:

in the 2005 version it became Table 41.1 – Maximum disconnection times

As far as I know the numbers have not changed at all for years, and we are now in the 2017 edition.

The figures in the UK regs are a direct copy without the bits for 120V land.

Hang on ... in 2001 edition, Table 41C (48A) is NOT an equivalent of what we have now in Table 41.1. It only applied in cases where the relevant part 7 (IEC 60364-7-7xx) reduced the maximum permissible touch voltage via equipotential bonding to 25 V AC or 60 V DC. See C|Lauses in 413.2 of the 2001 version.


For TN systems under usual conditions, see Table 41A and 41B of that standard ... which became what we now have as Table 41.1.

Do you have a copy of the table?


My understanding is that there is a 50 volt and a 25 volt touch limit based on the environment.

gkenyon:

There is no limit to touch voltage in IEC 60364-4-41 for TN systems (as today)


For TT systems, same disconnection times, but touch voltage limited to 50 V by equipotential bonding. This is not the same as today.


The disconnection times in Table 41 A (TN systems) are AC only but otherwise as they are for TN systems today, way back to 1992 at least, perhaps before ... As below for the 1999 Ed for example:


U0        Disconnection time (s)

120           0.8

230           0.4

277           0.4

400           0.2

>400         0.1

So where are they getting wet locations from?