High Zs reading how to rectify

[BristolSpark]

Hi Guys

Just wondering again your thoughts on the following if you have a high Zs reading, what is the best way of rectifying it.

say you have a BS60898 mcb type b 32a max Zs is 1.15 ohm. So if you took a reading when measured of say 2.23 ohms what is the best to fix this or remedy it.

I took a reading of this today on a socket in a porta cabin on a construction site. the RCD tripped ok at 23.6ms, so that was ok. But the Zs seemed awful.

Some good feedback would be great.

Thanks

 

[Mr Mark Sparks]

what was the ze at the cu and what was the r1r2 on the socket circ

 

[Spudnik]

Have a read

Page 21 OSG 3.6.1

 

[Guest123]

Construction sites are normally TT, therefore your max Zs is 1667ohms protected by 30mA RCD, but should be below 200.

Do you have a TT there??

 

[BristolSpark]

supplied from a pillar feeder. To a MDU then fed off to each cabin. We were nitially just testing that the rcd's worked in each cabin and Zs. Our remit does not cover the actual cabin test. So unsure on any actual tests or readings at c.u

I just know that the cabins are supplied from a B32 MCB from our MDU

 

[Mr Mark Sparks]

you need to find out if the whole cabin is that high or just that circ
what are the other cabin readings

 

[mark vernon]

Did you ever find a sollution to rectify your high Zs