TT earthing enquiry.

[driverJohn]

Hi do tt earth systems highly require a rcd, and if not are upfront rcds a must in the tt earthing systems? Cheers

 

[westward10]

Hi do tt earth systems highly require a rcd, and if not are upfront rcds a must in the tt earthing systems? Cheers

You have asked this question before in your other guises.

 

[Intoelectrics]

You have asked this question before in your other guises.

I wonder what John is driving at?

Sorry, Monday morning and not really feeling like work!

What other guises, just so I can avoid replying?

 

[timhoward]

What other guises, just so I can avoid replying?

Recent thread, now deleted I think, concern that up front RCD was ‘no longer accessible’.

 

[driverJohn]

Well I really needed the info that's why i bought my @ss back in this forum
So basically my question is if a TT earth system has no RCD will a upfront rcd be there behind the consumer bloody unit? Thanks. Need a answer for that only plz
and i blocked up the upfront rcd with tiles so if i trip it that would mean i wont be able to reset it if thats where the upfront rcds are located.
Can someone just tell me that cheers

 

[DPG]

Well I really needed the info that's why i bought my @ss back in this forum
So basically my question is if a TT earth system has no RCD will a upfront rcd be there behind the consumer bloody unit? Thanks. Need a answer for that only plz
and i blocked up the upfront rcd with tiles so if i trip it that would mean i wont be able to reset it if thats where the upfront rcds are located.
Can someone just tell me that cheers

I can confirm that if you have blocked the upfront RCD with tiles then you won't be able to reset it! We have no way of knowing what is there without seeing it.

I would suggest removing the tiles carefully and sending us a photo of what is behind them.

 

[driverJohn]

I can confirm that if you have blocked the upfront RCD with tiles then you won't be able to reset it! We have no way of knowing what is there without seeing it.

I would suggest removing the tiles carefully and sending us a photo of what is behind them.

ok, and do all tt systems have 100 percent a upfront rcd? cheers im nearly done going out of this forum

 

[timhoward]

For a TT system, fault protection can be either:
A) RCBOs in a consumer unit for all circuits
B) A consumer unit with a main switch RCD
C) An RCD in its own small 2 module enclosure (known as up-front RCD because it is between meter and CU)
D) older installations may have an Voltage Operated Earth Leakage circuit breaker between the meter and the CU but these are not effective, we’re removed from regs in 1986, and should be replaced.

Nothing at all is not a safe or compliant option. Once upon a time a water pipe earth was considered ok but that was many decades ago and isn’t the case now.

 

[DPG]

ok, and do all tt systems have 100 percent a upfront rcd? cheers im nearly done going out of this forum

In an ideal world yes, but in practice who can say what has been installed over the years. Be interesting to see what you find - to be honest nothing in the system should be tiled over, so they need removing either way.

 

[davesparks]

Well I really needed the info that's why i bought my @ss back in this forum
So basically my question is if a TT earth system has no RCD will a upfront rcd be there behind the consumer bloody unit? Thanks. Need a answer for that only plz
and i blocked up the upfront rcd with tiles so if i trip it that would mean i wont be able to reset it if thats where the upfront rcds are located.
Can someone just tell me that cheers

Every installation is different, nobody can tell you exactly what is installed without seeing it.

We can tell you what should be installed as per current regulations, but there is no guarantee that your installation complies with current regulations.

So if your consumer unit does not have RCD protection for every circuit on a TT system then yes there should be an RCD installed before the consumer unit.

 

[driverJohn]

Yeah thats my question done with cheers everyone however will connecting the main earth with a metal pipe not require any rcds?
And how to check if the main earth is connected to a pipe instead of a rod.
John

 

[DPG]

Yeah thats my question done with cheers everyone however will connecting the main earth with a metal pipe not require any rcds?
And how to check if the main earth is connected to a pipe instead of a rod.
John

You need an RCD and also an earth connection. I really would recommend getting an electrician in to check this out - it could well be dangerous.

Or, as I said, post a couple of photos - one of your consumer unit and one of what is behind those tiles.

 

[davesparks]

Yeah thats my question done with cheers everyone however will connecting the main earth with a metal pipe not require any rcds?

It will still require RCD's for fault protection.

(technically if it is a large amount of buried pipe, which you own, is on your property, has a very low resistance to earth, is protected against being removed or disconnected, doesn't carry any gas or other flammable/explosive fluid and is suitable for use as an earth rod then you may not need RCDs for fault protection. But you would still need RCDs for other types of protection)

And how to check if the main earth is connected to a pipe instead of a rod.
John

Visually, follow the cable and see what it connects to.

 

[timhoward]

My concern is that there is apparently considerable uncertainty about whether this installation would disconnect under fault conditions as opposed to sitting there with live metalwork ready to kill someone.
From the questions asked I don’t think we are going to be able to reliably guide the OP to an answer.
This could be a life or death matter and as DPG said the installation really needs looking at asap.

I also wouldn’t want to unduly raise the OP’s hopes about a suitable and compliant earth via pipework as in my experience it’s rare to find compliant examples of this in domestic properties, at least where I live. I slightly regret even mentioning water pipes now as they are almost certain to be a red herring.

 

[driverJohn]

yes mate can you remove this entire thread, i give up. With this thread it might motivate me in touching the cutout fuse so might aswell remove this thread

 

[driverJohn]

+ i got duplicate accounts so i will have to be banned for that

 

[DPG]

yes mate can you remove this entire thread, i give up. With this thread it might motivate me in touching the cutout fuse so might aswell remove this thread

Not sure what the problem is here. People have taken time to give you thoughts and opinions. Just open up the tiling and we can see what's there.

 

[Dave OCD]

I'm afraid this is another one where despite very sound and safety critical advice the OP seems hell-bent on disregarding everything to avoid an RCD , potentially lethal. We might as well give up on this one...

 

[nicebutdim]

My concern is that there is apparently considerable uncertainty about whether this installation would disconnect under fault conditions as opposed to sitting there with live metalwork ready to kill someone.
From the questions asked I don’t think we are going to be able to reliably guide the OP to an answer.
This could be a life or death matter and as DPG said the installation really needs looking at asap.

I've seen TT installations where a fault meant live metalwork - not a fun situation.

 

[driverJohn]

yeah true but the lucky man here got earth leakage circuit breakers, but its kind of disappointing to see that as all the pipes are connected with the earth and under a fault condition not all current flows to the elcb as some goes to the other pipes and most luckily they have lower impedance compared to the breaker.