Would you accept a Ze of 199Ω on a TT Installation which also has an RCD.

[HappyHippyDad]

I realise many threads have been discussed around the (maximum) figure of 200Ω for external earth fault loop impedance (as given by BS7671) on a TT, however I'd be interested to see what proportion would and wouldn't accept this figure.

Hopefully we wont get into semantics of was it a dry day, wet day etc. Its just a straight forward simple poll seeing how many would accept the figure given by BS7671.

This will be an anonymous poll.

EDIT : I SHOULD HAVE SAID :

"WOULD YOU ACCEPT A Ze OF 199 Ω ON A tt INSTALLATION WHICH ALSO HAS RCD PROTECTION"

 

[Leesparkykent]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

Should the option on the poll be below 200 ohms?

 

[HappyHippyDad]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

Should the option on the poll be below 200 ohms?

Yes.. bugger!

Can You change it mods?

I should have put 'Would you accept a Ze = 199Ω on a TT Installation which also has 30mA RCD protection'.

Hopefully you'll all see this and vote accordingly :smile5:

 

[123]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

Does everything need to be a poll?

We'll be having designs put to a poll soon!

 

[Farmelectrics]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

I'd be hoping to get a lower reading than that however most books say max value for a tt is 200 ohms

 

[Octopus]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

200 no


199 yes.

unless you are with the NICEIC and then its

100 no


99 yes

:rant::rant::rant:

 

[Leesparkykent]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

Yes.. bugger!

Can You change it mods?

you should change the option IMO to would you accept a figure between 100ohms and <200ohms on a TT installation which also has an RCD

 

[ImpededLoop]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

Does everything need to be a poll?

We'll be having designs put to a poll soon!

Like any other thread, you have the option to ignore it if it doesn't interest you.

If it interests nobody it'll soon drop off the bottom of the page....

 

[123]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

And I'd like to think that all TT systems will have an RCD, multiple RCD's in fact. Even if they meet TN readings I'd still be inclined to have an upfront Type S RCD...

 

[baldsparkies]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

Just don't show it to Tony Cable.
He will only frown at you for not listening to those who are above and beyond BS 7671.

 

[JD6400]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

Yes.. bugger!

Can You change it mods?

I should have put 'Would you accept Ze = 199Ω on a TT Installation which also has 30mA RCD protection'.

Hopefully you'll all see this and vote accordingly :smile5:

Do you mean Ra

 

[telectrix]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

let's put this stupid 200Ω myth to bed once and for all. it is NOT a max. figure in BS7671, which clearly states that a value above 200Ω is liable to be unstable. there is no mention of a max. figure in any BS7671.

for the record, i'd not accept it and i can't vote in the poll as there is a forum glitch. paul m is looking into it.

 

[sparksburnout]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

let's put this stupid 200Ω myth to bed once and for all. it is NOT a max. figure in BS7671, which clearly states that a value above 200Ω is liable to be unstable. there is no mention of a max. figure in any BS7671.

for the record, i'd not accept it and i can't vote in the poll as there is a forum glitch. paul m is looking into it.

Tel why is your text getting so small. (PS I've bought the bloody bonneville!!!!!)

 

[HappyHippyDad]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

Do you mean Ra

I refer you to the word 'semantics' in the OP.

 

[GMES]

Re: Would you accept a Ze of 200Ω on a TT Installation which also has an RCD.

I would want to see reading of less than 10, so keep swinging that hammer!!