Zs values...

[SSE]

Anybody know where that post wentt that showed you the acceptable zs values for each protective device? Thought it was a sticky but can't seem to find it anywhere. And before anybody says get a regs book I'm waiting for it to be delivered!

 

[ezzzekiel]

get a regs book out

 

[ian.settle1]

get a regs book out

Thats as funny as a piece of Pork at ajewish wedding

Read his last line

 

[ezzzekiel]

i did that was the joke

 

[scotsparky]

pages 102,103 of the OSG

Ther pre calculated for the 80% rule

 

[bugsy]

Who's got the apple sauce!

 

[Sintra]

It's in this thread useful references.

http://www.electriciansforums.net/e...electrical-forum/15761-useful-references.html

 

[trebor]

Anybody know where that post wentt that showed you the acceptable zs values for each protective device? Thought it was a sticky but can't seem to find it anywhere. And before anybody says get a regs book I'm waiting for it to be delivered!

dont forget good old Ohms Law for the 60898 cb`s which are are going to be the most common device used, its very handy when the reg book is not at hand

type b 5 x In
type c 10 x In
type d 20 x in

for all disconnection times from 0.1 to 5 secs

eg 32A type B x 5 = 160
230/160 = 1.44 agrees with regs as cold value x .80 = 1.15 ohms max Zs