Max Zs

[steptoe]

right,

my tuppence hapny worth.

I could be wrong, I usually am,

BUT

in 17th I dont think you are permitted to use the 50v rule anymore.

to use the 50v rule is a DEVIATION from BS7671.!?

if you are allowed to use it can someone point me to the reg please?

I deviate from the regs on a VERY regular basis, as readers of my posts will know, and I use the 50v rule to ensure my installations are safe,

BUT its NON COMPLIANCE with BS7671-2008,

DEVIATIONS FROM REGS BOX TICKED. ; \

NOW,

what other hole do you want blew in that stoopid big red book of yours Eammon.?

che che noi.

Guiness Drink

 

[PAUL M]

I'm sorry admin 2 - hackles went up :|

i dont doubt it ,but i am merely pointing out that when it comes to advanced electrical installation matters you may struggle to fully understand some of the more finer points shall we say,so instead you pick holes in a guy`s character you dont even know,you obviously have a problem with new guys,but hey thats your problem not ours. so maybe you are a tad insecure?:and on that note i bid you goodnight sir.

 

[Apache]

i dont doubt it ,but i am merely pointing out that when it comes to advanced electrical installation matters you may struggle to fully understand some of the more finer points shall we say,so instead you pick holes in a guy`s character you dont even know,you obviously have a problem with new guys,but hey thats your problem not ours. so maybe you are a tad insecure?:and on that note i bid you goodnight sir.

lol

I like newbies. I like (almost) all of you. You can read my thoughts here and my justification.

:|

 

[kme]

lolI like newbies. I like (almost) all of you. You can read my thoughts here and my justification.

:|

I am soNOTgetting involved in this........

Apache - you mustn`t put your hackles up. Someone`ll think you`re dangerous, and report you to the RSPCB:^O:^O:x

(BTW - "bovines"): 4 legs good

 

[Apache]

I am soNOTgetting involved in this........Apache - you mustn`t put your hackles up. Someone`ll think you`re dangerous, and report you to the RSPCB:^O:^O:x

(BTW - "bovines"): 4 legs good

Apache can do a bloody good mad cow impression when needed

Good job it's not 1988 or I'd have been shot and rendered

 

[kme]

Why would someone draw a software picture of you??

Oh. Duh. The "Mr. Fawkes" style of rendering?

mad? Not flippin` likely!

 

[a1]

Gentlemen, I would like to draw your attention to This Thread Here.

 

[Shakey]

And well done Admin, I have come on here trying to have a meaningfull debate, in my own style, and comments such as 'massaging ones ego' and 'arrogant' are unhelpfull are best and hurtful at worse, i want to fit in and contribute, but some of the senior memebrs are making it SERIOUS hard work

Lets please stop this and get down to talking about electrical installations PLEASE, or i fear my stay here maybe shortlived

 

[a1]

Agreed Shakey.

 

[SPECIAL LOCATION]

Apache i hate Gloss:_| :_| Do not mind a bit of Eggshell though

Mind you i am not walking on them:^O:^O

Wheres our furry friend??

Morning SSAB?

not sure if I class as furry friend?

I have actually got quite a bit of work to sort at the moment...

and what with all the increased post traffic...

it may take a bit longer to get back to post a constructive reply...Blushing

specially as it appears I got the 'great big capatin argument hat' on? :|

I shall have to going back and study my politeness and etiquette book...?

:|

 

[no1electrician]

just wondering what the max Zs is for30a BS3036

25a BS3871 type 2

I dont think either of these are covered by BS7671-2008, but are perfectly acceptable protective devices.

generally I simply put a note on the cert explaining that 'no max Zs value available in BS7671-2008 for protective device XXXXXXXX'

anyone got some other suggestion.

max zs for bs3036 is in the book tables41.2&41.4

bs3871 have been superceded i don't know where you'd get 230v values from for a PIR

wayne

 

[springcrocus]

Is this (page 5 onwards) any help?

 

[kme]

NICE post. Very handy doc.

On the PIR I mentioned on another thread, max ZS for 3871 are given as:

5A - 5.48

10A - 1.92

15A - 1.83

32A - 0.6

My understanding is that these are all 80% figures.

HTH

KME

 

[steptoe]

NICE post. Very handy doc. On the PIR I mentioned on another thread, max ZS for 3871 are given as:

5A - 5.48

10A - 1.92

15A - 1.83

32A - 0.6

My understanding is that these are all 80% figures.

HTH

KME

those look suspiciously like type c figures kme,

are there any for type 2 anywhere?

good link also,

BUT,

its NOT BS7671 so it cant be used as max Zs values on the NIC certs, can it?

NOT that Im really bothered TBH, was just making a point about how most of this trying to stick to the regs is a joke as so many houses dont even have a reference point available anymore.!!!

X(X( X(

 

[kme]

The figures above were quoted as max Zs by a large, national company; on a PIAT, using NIC certs mate. I have the PDF of the whole thing, and it`s a bit of a monster to wade through. (1 inspector throughout - hotel with 150+ rooms)

I`d think twice before taking that one on.......

 

[sirsparkabit]

Morning SSAB?not sure if I class as furry friend?

I have actually got quite a bit of work to sort at the moment...

and what with all the increased post traffic...

it may take a bit longer to get back to post a constructive reply...Blushing

specially as it appears I got the 'great big capatin argument hat' on? :|

I shall have to going back and study my politeness and etiquette book...?

:|

Not at all mate if anyone needs to studt more its me

 

[Tazmanracer]

those look suspiciously like type c figures kme,are there any for type 2 anywhere?

good link also,

BUT,

its NOT BS7671 so it cant be used as max Zs values on the NIC certs, can it?

NOT that Im really bothered TBH, was just making a point about how most of this trying to stick to the regs is a joke as so many houses dont even have a reference point available anymore.!!!

X(X( X(

Ready to be shot down and all, i'm very much still learning so be kind. When I saw your first post in the thread, don't ask me what page lol, I thought i'd look it up, in my new shiney GN3 (Orangey-Yellowey Cat-Sickey Colour) and came up with:-

BS 3036 30 amp - 0.9

and

(now i've lost what sizes i was looking up)

BS 3871 Type 2 - Rating Zs

5 5.3

6 4.42

10 2.65

15 1.77

16 1.66

20 1.32

25 1.06

30 0.88

32 0.83

Tables B.1 and B.4

The BS 3871, is classed the same as a BS EN 60898, BTW if this is all wrong can some one explain. Thanks

 

[professional]

I think that the one thing that is being forgotten in this `debate` is the fundamental differences in protection on TT and TNS/TNCS systems. The reason why the max tabulated (or 80%) values on a TNS/TNCS system must still be adhered to wherever possible is that the possibility of the rcd failing has to be taken into account. Clearly on a TT system there is no external `earth` to back up the rod but the regs are merely ensuring that the installer is making best use of the earthing arrangements available under the relevant circumstances. Surely, if an external earth of low impedance is available then it makes sense to make use of it in the event of a problem occurring with the installation?

Remember, the regs are guidlines to best practice with regard to safety - not an instruction manual for installers.