Domestic PIR & maximum permitted Zs on a TT system

[ADS]

The column states Max ZS does it not ?

Yes, mine says 'Maximum permitted Zs'

 

[batty]

Where would you put those figures on the EIC or PIR ? (ie what column etc)---------- Post Auto-Merged at 23:36 ---------- Previous post was made at 23:36 ----------

Yes and no go buy your own book :slap

I have one just to lazy to read it at the moment and busy on here with all the present going ons.

 

[ADS]

And you you put the rcd value in then ?Shame on you....

Not following you.???

One for you, Canoeboy, seems you like to wind up -

17th edition install, sockets and lights.

Sockets 32A MCB and 30 mA RCD protected, but not wanted on lighting - surface wiring in pvc conduit, 6A MCB.

TT install with Ze of 130 ohms and 100mA time delayed RCD up front (to allow discrimination)

What would you put in our 'Max permitted Zs' box for the lighting circuit

 

[steptoe]

N/A

anyone know why?

---------- Post Auto-Merged at 00:19 ---------- Previous post was made at 00:18 ----------

EDIT, 1667 is not permitted under BS7671 using a 30mA RCD

 

[ADS]

Steptoe!!!!

He's gonna love you even more now you've given the game away!

---------- Post Auto-Merged at 00:23 ---------- Previous post was made at 00:21 ----------

You dont specify Type of MCB ?Not a wind up, perhaps you have a problem interpreting ?

Perhaps my english isnt that good :slap

Doesn't matter what type of MCB it is, your earth fault protection for the lighting circuit is coming from the 100mA RCD

 

[ADS]

6 Amp Hager MCB

A picture as well - in case you're still confused! Guinness

 

[steptoe]

Doesn't matter what type of MCB it is, your earth fault protection for the lighting circuit is coming from the 100mA RCD

how so?

normal 100mA RCDs dont have any earth fault protection, or have I got it all wrong again? :|

 

[ADS]

how so?normal 100mA RCDs dont have any earth fault protection, or have I got it all wrong again? :|

Okay, so a fault to earth on the lighting circuit is going to trip..................?????? the MCB?? Doubtful!

---------- Post Auto-Merged at 00:42 ---------- Previous post was made at 00:40 ----------

Now your changing the subject ?Do you want to stick to the question in Hand ?

Hello - Knock Knock ? Anyone there ?

The question remains the same........what are you putting in the box?

 

[ADS]

Now your changing the subject ?Do you want to stick to the question in Hand ?

Hello - Knock Knock ? Anyone there ?

Right back at you!

 

[steptoe]

Okay, so a fault to earth on the lighting circuit is going to trip..................?????? the MCB?? Doubtful!

may not trip the RCD either,

there is a lot more to it than simply banging a rod in and sticking a 100mA front end on

I feel a poll coming on.......

 

[ADS]

Okay, so a fault to earth on the lighting circuit is going to trip..................?????? the MCB?? Doubtful!may not trip the RCD either,

there is a lot more to it than simply banging a rod in and sticking a 100mA front end on

I feel a poll coming on.......

Granted.

The figures might not work out anyway.....disconnection times etc.

It's just an example to see what your son would put in the 'Max Permitted Zs' box.

 

[steptoe]

so, even though you are admitting I 'may' be correct, and you havent done any calcs you still want a sly insult at me?

water off an oilskinned donkey jacket to me...

 

[ADS]

so, even though you are admitting I 'may' be correct, and you havent done any calcs you still want a sly insult at me?water off an oilskinned donkey jacket to me...

Once again, not a dig at you, a dig at 'Canoe' - only your Son, Dad, Brother could love you as much as he does lol.

Be interesting to see what he thinks about you being insulted by the thought of him being your son, though - unless he's about 60 ha ha

 

[steptoe]

:slap

 

[kme]

Kiddiewinks - stop it! You know there`ll be consequences if you can`t "play nice".....................

 

[steptoe]

ADS has kind off given me worship status to be honest - Son of Steps

you are easy pleased.! :slap

Im just wondering how old Im supposed to be!!! :_|

 

[ADS]

Canoeboy (a.k.a. Harold), you won't answer questions - you go around in circles and off topic - I can't have a decent discussion with you so, rather than fall out with you, I've put you on my ignore list.

Something else to be proud of - there's only you on it! - even Steptoe doesn't qualify. :^O

 

[steptoe]

if only, :slap

 

[VoltzElectrical]

N/Aanyone know why?

---------- Post Auto-Merged at 00:19 ---------- Previous post was made at 00:18 ----------

EDIT, 1667 is not permitted under BS7671 using a 30mA RCD

Just came upon this thread and I don't understand this comment. Can anyone explain.

---------- Post Auto-Merged at 22:53 ---------- Previous post was made at 22:48 ----------

how so?normal 100mA RCDs dont have any earth fault protection, or have I got it all wrong again? :|

Am I missing something? If an RCD doesn't provide earth fault protection... what DOES it do?

 

[apprentice87]

Hi all,

To come back to the question posed by Steps in post No:30,

"N/A

anyone know why?"

Newbie [me!] answer;

Because the MCB for the lighting circuit is not providing earth fault protection, merely overcurrent protection, and so "Zs" for this device is wholly irrelevant, earth fault protection for this circuit being provided by the front end RCD ???????

john...