garden shed Ze

[Pete999]

They are still in parallel L and N are the same where ever it comes from even if the supply is fed off the sockets its still Live and neutral , if it was in series then the live would enter the first rcd come out of the neutral of that RCD as a live to the live of the next RCD and the neutral would be connected to the last RCD,

View attachment 25957

Nick I think you may have misunderstood the point, 2 RCDs on the same leg of a circuit is not recommended unless some form of discrimination has been applied, perhaps with using a time delay RCD or 2 of differing mA ratings.
I get the impression you are trying to make a point about the difference between Series and Parallel, most of us know the difference.

 

[Octopus]

They are still in parallel L and N are the same where ever it comes from even if the supply is fed off the sockets its still Live and neutral , if it was in series then the live would enter the first rcd come out of the neutral of that RCD as a live to the live of the next RCD and the neutral would be connected to the last RCD,

View attachment 25957

So its Ok to have 2 RCD's in series then? I'm obviously missing your point.

The socket circuit supplying the shed is protected by a 30mA, then the shed has a 30mA RCD in it??

Thats how I read the OP

 

[nickblake]

Nick I think you may have misunderstood the point, 2 RCDs on the same leg of a circuit is not recommended unless some form of discrimination has been applied, perhaps with using a time delay RCD or 2 of differing mA ratings.
I get the impression you are trying to make a point about the difference between Series and Parallel, most of us know the difference.

Yes Pete i fully understand this and im not misunderstanding the point but when it is referred to as series it is incorrect ,they are in parallel simple as , and im not having a jab at any one, its just something that keeps cropping up and just wanted to point it out , any way every one nit pic's my posts so its my turn Lol

 

[Silly Sausage]

I disagree, RCDs aren't a load, they are devices connected in series, as in one is downstream from the upstream one!

 

[Pete999]

Yes Pete i fully understand this and im not misunderstanding the point but when it is referred to as series it is incorrect ,they are in parallel simple as , and im not having a jab at any one, its just something that keeps cropping up and just wanted to point it out , any way every one nit pic's my posts so its my turn Lol

I wasn't nitpicking mate just trying to clarify

 

[nickblake]

I know mate didnt think for a moment you where , archi they are still in parallel regardless of if they are a load or not lives are connected to lives neutrals to neutrals that is parallel

 

[Octopus]

I know mate didnt think for a moment you where , archi they are still in parallel regardless of if they are a load or not lives are connected to lives neutrals to neutrals that is parallel

ha ha, I see your point!

I still say having 2 x 30mA RCD's on the same circuit is bad practice - whether they be parallel or series!!

 

[Silly Sausage]

I know mate didnt think for a moment you where , archi they are still in parallel regardless of if they are a load or not lives are connected to lives neutrals to neutrals that is parallel

OK, they're not electrically in series, L & N are effectively electrically separate, but you could argue they are magnetically in parallel!

Me and everyone else will keep refering to them as being in series.

 

[Barry White]

Agree they are in series remove or trip the first and the second is dead in parallel it would still be energised. Either one or both may trip in fault conditions therefore no discrimination is the point that being made.
If the feeds were in parallel only the the one with a fault would trip

 

[davesparks]

Yes Pete i fully understand this and im not misunderstanding the point but when it is referred to as series it is incorrect ,they are in parallel simple as , and im not having a jab at any one, its just something that keeps cropping up and just wanted to point it out , any way every one nit pic's my posts so its my turn Lol

The coils of the RCD are in series rather than parallel, the current passes through the first live coil, then the second, then the second neutral coil then the first

 

[davesparks]

I know mate didnt think for a moment you where , archi they are still in parallel regardless of if they are a load or not lives are connected to lives neutrals to neutrals that is parallel

They are in series, on protective device downstream of another is series.

If you put one SP mcb after another it is series and you get the benefits of a series connection.
Put one DP mcb after another it is series,
Put one RCD after another it is series.

Current passes through one and then the other, if it was paralell then current would pass through each one without passing through the other.

 

[telectrix]

deffo series. in and out the first one then into the second.

 

[ChrisElectrical88]

Don't care. Series , parallel, cheese sandwich.

 

[LeeH]

Without seeing the installation I would say the ZE is taken at the incomer to your shed DB with the earth disconnected and on your cert marked down as ZE at the DB

That would be the Zdb or Zs. The Ze can only be 1 place can it not?

Cannot be arsed to read all the posts on this thread for obvious reasons.

 

[telectrix]

a series cheese sandwich is with tomato. a parallel one is with onion.

 

[Guest77]

A painful thread, very very painful.

 

[Plonker 3]

5 pages on how to take a Ze, is this the next generation of sparks standard now? No wonder the money we earn is coming down.

 

[Guest77]

Yep the standard is now lower than a jack russels wedding tackle, we are close to a snakes belly level.

 

[Plonker 3]

Evening Mike

 

[Guest77]

Evening Buddy

 

[GMES]

..

 

[Silly Sausage]

What's the internet?

 

[Plonker 3]

View attachment 25965..

thats need modifying slightly for the Electrical Trainee to read " I don't know what I am doing, but what I need to know i can ask on EF"

 

[Plonker 3]

What's the internet?

Its what you get from the bank when your account is in credit.

 

[Guest77]

https://www.youtube.com/watch?v=MSQDzsQvJa8

 

[telectrix]

or this

 

[HappyHippyDad]

That would be the Zdb or Zs. The Ze can only be 1 place can it not?

Cannot be arsed to read all the posts on this thread for obvious reasons.

I have, and feel that I have lost 10 minutes of life! :crazy:

 

[telectrix]

i've just connected the megger to my extremities and told 'er indoors to press the --- if i doze off.

 

[GMES]

I only have one thing to say too the op for starting this thread!!

 

[DNO]

Your query- where do I check Ze--Ze is external loop impedance--so its at the DNO service, or more practically-- the distribution board adjacent.

 

[£££sjim]

One thing about this thread to some of you know it all type people it certainly caused some interesting results and varying options. Some helpful some sarcastic. We all have various interpretations of the rules and regulations but we are not infallible Is that not why we refer to our on site guides and BS7671:2008 (2011) or even the Electricians Forum. That is excluding the I'm too clever to part with my knowledge or experience. A joke is a joke but bugger a pantomime. Amature armature ha ha armadillos
Any advise on wiring a three pin plug from China from Ebay :fuk2:

 

[Geordie Spark]

One thing about this thread to some of you know it all type people it certainly caused some interesting results and varying options. Some helpful some sarcastic. We all have various interpretations of the rules and regulations but we are not infallible Is that not why we refer to our on site guides and BS7671:2008 (2011) or even the Electricians Forum. That is excluding the I'm too clever to part with my knowledge or experience. A joke is a joke but bugger a pantomime. Amature armature ha ha armadillos
Any advise on wiring a three pin plug from China from Ebay :fuk2:

No, but I can tell you where to plug it in after you've wired it.

 

[Geordie Spark]

Its what you get from the bank when your account is in credit.

I wouldn't know about that ..... I have more creditors who I pay £1 per month to that the late great Little Waster Bobby Thompson could ever aspire to.

(Google Bobby Thompson ---- Geordie humour at it's finest!)

 

[Geordie Spark]

I have, and feel that I have lost 10 minutes of life! :crazy:

I wish I had the luxury of 10 minutes to lose.

 

[Geordie Spark]

Yep the standard is now lower than a jack russels wedding tackle, we are close to a snakes belly level.

Which is only marginally higher than a politician's morals.

 

[Octopus]

One thing about this thread to some of you know it all type people it certainly caused some interesting results and varying options. Some helpful some sarcastic. We all have various interpretations of the rules and regulations but we are not infallible Is that not why we refer to our on site guides and BS7671:2008 (2011) or even the Electricians Forum. That is excluding the I'm too clever to part with my knowledge or experience. A joke is a joke but bugger a pantomime. Amature armature ha ha armadillos
Any advise on wiring a three pin plug from China from Ebay :fuk2:

Well. Some of the so called know it alls clearly know more than you and you haven't answered the point about 2 rcd in series have you?

 

[Silly Sausage]

Well. Some of the so called know it alls clearly know more than you and you haven't answered the point about 2 rcd in parallel have you?

:smilielol5:

 

[nickblake]

right I have been pondering this one and come up with the conclusion we are both right:stooge_curly: , if you look at RCD's they will be in series when in circuit runs through the rcd mcb through the load in series , correct , im happy with that , how ever close the contacts of the switch and mcb's the coils will then be in parallel ,and this is the reason i look at RCD's as being in parallel so the conclusion is rcd's are in the series parallel formation :stooge_curly:

 

[£££sjim]

It's in series. Numpty. From CU in house to socket in garden to a 13amp plug to shed then into shed CU and RCD and three MCBs. In my book Series. Can't be in parallel as the second circuit would start before first RCD ! Can't remove first RCD because it is protection for outside socket. But to be correct the shed should have had its own supply. But I knew this. So to be safe with the extenson feeding shed CU I wanted to check if there was a problem regarding Ze. So I received abuse from some NHs and some useful information from others. Also quite a bit of disagreement amongst your selves. ?.SELV ?
UOTE=Archy Styrigg;992820]:smilielol5:[/QUOTE]

 

[Pete999]

Look we all know you shouldn't install 2 RCDs of the same characteristics on the same circuit, we have done this to death 79 posts and still no settled, give it a rest