Earth Loop Impedance Table 17th Edition

[WarrenG]

Hi Guys,

Here is a handy 17th Edition Loop Impedance Table.

This table gives you a direct comparison with your Zs tests results and is calculated @ the 0.8 Rule of Thumb figure.

Enjoy!

Warren

 

[DanBrown]

Hi Guys,

Here is a handy 17th Edition Loop Impedance Table.

This table gives you a direct comparison with your Zs tests results and is calculated @ the 0.8 Rule of Thumb figure.

Enjoy!

Warren

What do you mean by the 0.8 rule of thumb figure?? What is that??

 

[jeremy]

DO you have to point 8 of your thumbs at something?? I've got 2 and am willing to lend tham out!

 

[WarrenG]

When taking a Zs reading, we cannot use the direct measurement to compare with the Zs earth loop tables in the Regs.

We have to take into account ambient temperature (at the time of test) and the conductor operating temperature. Both have an effect on the resistance. There is therefore a 0.8 rule to apply for your max Zs reading.

Example:

Regs book Page 49, Table 41.3, Type B BS EN 60898, 6A Zs = 7.67 ohms

7.67 x 0.8 Rule of Thumb = 6.13 ohms

17th Table - BS EN 60898, 6A Zs = 6.13 ohms

So the table gives you a direct comparison for your Zs readings.

Hope this helps!

Warren

 

[DanBrown]

Yeah, thanks for that warren..
Where does the figure 0.8 come from? is it in onsite guide or big regs book?.

 

[jeremy]

OSG. The big one quotes the max allowed under perfect conditions then you have to adjust it by allowing for max operating temp etc. The 0.8 is allowing for worst case scenario but if your Zs is greater than the 0.8 adjusted figure it doesnt necessarily mean it has failed there are longer calcs that can be done to take into account each individual installation. Hope this is of use.

 

[hugo]

Warren

You posted a table with max eli details earlier this year. Im new to the forum, can you tell me how to get a hold of the table.

Cheers

Hugo

 

[scotsparky]

hugo the Max eli are the tabulated ones in the regs.

 

[BigD62]

hi warren
Sorry cannot find the table you describe
regards
BigD62

 

[hugo]

Thanks. I've got the tables in the Regs, but I thought that someone had taken the time to put them into another format; Word or Exel.

Just lazy mate!

Regards

Hugo

 

[old dog]

the tables in the on site guide and guidance note 3 give the values after the 0.8 calculation
bs 7671 gives the max before calculation
have a look on page 111 table b.4
osg page 103 table 2 d
for examples

 

[Guest 004]

Hi Guys,

Here is a handy 17th Edition Loop Impedance Table.

This table gives you a direct comparison with your Zs tests results and is calculated @ the 0.8 Rule of Thumb figure.

Enjoy!

Warren

where is it??
and does anybody have 100% values?
These 80% values are also in the NICEEIC test book

 

[NoSparks]

Sory I'm not used to this forum yet. You say "here is" how do I get to it?

 

[trix]

Mr. Enigma, B.S.7671 pages 48 to 49

Hope this helps.

 

[Guest 004]

Here are 80% values in xcel format http://spreadsheets.google.com/ccc?key=0AmFMA2yG7zsjdEd5Q1ZBdDRsX0I4S3p2N1FnVS1kMXc&hl=en_GB

Her are the 100% values http://spreadsheets.google.com/ccc?key=0AmFMA2yG7zsjdG91TFNoc3dMOE00NVJlSlIteWpCZWc&hl=en_GB