earth rods???

kramer1

hi all. first post been lurking for a while.

i have a house in dublin seven that is not neutralized but has two earth rods, does this sound right, and is it safe or should i get a sparks to look at it?

Any advice/comments would be greatly appreciated

M cebee

tn-c-s is pretty standard here -i would get it looked at


where TT or 'direct earthing' is used you require rcds for automatic disconnection due to the higher fault loop-impedance

how do you know it's not neutralized-have you looked at the cut-out ?

paulb79

hi two earth rods is a problem you should have one removed ,the supply to your house is tncs so it should be netruelised

kramer1

thanks very much, ill get it looked at

sparkfireman

Yeah just remove 1... It has the potential to cause problems between you and the ESB if there is a fault!

Bruthal

TT systems sometimes use more than 1 earth rod to bring the Impedence down, Is it a house in a housing estate, or on its own with its own transformer. If its the second case i`d ask the esb about it. Does the MCB board have a main RCD on it?

If its one earth conductor from the earth bar in DB down to the 2 earth rods i would of thought they can both be left in anyway.

Are any houses done with TT now?

M cebee

robbie7730 wrote: »

TT systems sometimes use more than 1 earth rod to bring the Impedence down, Is it a house in a housing estate, or on its own with its own transformer. If its the second case i`d ask the esb about it. Does the MCB board have a main RCD on it?

If its one earth conductor from the earth bar in DB down to the 2 earth rods i would of thought they can both be left in anyway.

Are any houses done with TT now?

doubt it-it's very common in the uk although they seem to be moving towards tn-c-s

in the old days you couldn't trust neutralized on the long LV lines anyhow-direct earthing was common in rural areas but it seemed to be badly done-

bad earth electrode resistance and no ADS via rcd that i ever saw

Bruthal

M cebee wrote: »

doubt it-it's very common in the uk although they seem to be moving towards tn-c-s

in the old days you couldn't trust neutralized on the long LV lines anyhow-direct earthing was common in rural areas but it seemed to be badly done-

bad earth electrode resistance and no ADS via rcd that i ever saw

They were the days of 1 light and a socket as well. Id say the days of everthing on RCBO`s are on the way.

M cebee

ya for domestic

dual-rcd boards are common in the uk


all circuits 30mA protected -lights split over both rcds


won't happen for commercial lighting etc for obvious reasons


dunno how the cooker manages on the rcd but they do afaik-i'll post a link for a board when i find one

Bruthal

M cebee wrote: »

ya for domestic

dual-rcd boards are common in the uk


all circuits 30mA protected -lights split over both rcds


won't happen for commercial lighting etc for obvious reasons

Yes domestic is what i should of said alright. Its domestic i was thinking of although my experiences were mostly industrial.

Although i was thinking of RCBO`s for each circuit,

kramer1

thanks for all the answers,


its an old house <maybe hundred years> in an estate in town, the wiring looks reasonably new but kind of cobbled together. the two earth rods are ran from the
earth bar on the consumer unit down to the ground on separate 16sq earth cables, there is no neutralizing wire going back to the cut out.
at the minute we re gutting the place and are only using one socket as our temporary supply , this is definitely the only socket on this circuit.
do i need to get a sparks or esb in to get this problem resolved before i do any more work or can i leave until th job is ready for first fix?
ty

Bruthal

kramer1 wrote: »

thanks for all the answers,


its an old house <maybe hundred years> in an estate in town, the wiring looks reasonably new but kind of cobbled together. the two earth rods are ran from the
earth bar on the consumer unit down to the ground on separate 16sq earth cables, there is no neutralizing wire going back to the cut out.
at the minute we re gutting the place and are only using one socket as our temporary supply , this is definitely the only socket on this circuit.
do i need to get a sparks or esb in to get this problem resolved before i do any more work or can i leave until th job is ready for first fix?
ty

Are you rewiring the house during renovations? If not id have it checked anytime before you do any major work in case it is recommended you have it rewired.

Carlow52

Would someone be kind enough to explain what the following extracts mean from posts in this thread:

there is no neutralizing wire going back to the cut out.

and

tn-c-s

and

TT systems sometimes use more than 1 earth rod

Thanks

Bruthal

Neutralizing from the cutout is connecting the earth bar on an MCB board to the Supply company Neutral at the meter fuse unit to provide a low impedence/resistance for earth faults within an installation.
The earth bar also has a 10 square earth wire down to the earth rod.

TT is like above but has no neutralizing connection, and is of a higher impedence/resistance and so this type of installation is not really used here now, and if it is used an RCD protects the entire installation.
TT is tera tera for earth-earth or direct earthing i would think.

TN-C-S is a neutralised system like the first one, used in ireland, it means the earthing is neutralised, and the C references the fact that from the esb transformer to the esb cutout/meter the neutral and earth are combined, then after the main cutout(fuse)/meter the earth and neutral are seperate which is the S. Tera-Neutral-Combined-Seperate.

I think thats right, but i will probably know soon enough if not:)

Carlow52

Thanks Robbie:

My set up is as follows, which is why I asked:

Red/Black from ESB fuse where 'swa' from ground terminates and then from meter to MCB

MCB has 63A RCD beside fuse and is marked sockets only

skinny earth wire to earth rod

House is c 40 years old but the MCB is new enough, all mcb's

Other than upgrade the skinny eath to 10sq, any other suggestions?
Thanks

Bruthal

Carlow52 wrote: »

Thanks Robbie:

My set up is as follows, which is why I asked:

Red/Black from meter to MCB

MCB has 63A RCD beside fuse and is marked sockets only

skinny earth wire to earth rod

House is c 40 years old but the MCB is new enough all mcb's

Other than upgrade the skinny eath to 10sq, any other suggestions?
Thanks

If the wiring is also 40 years old then rewiring might be a suggestion, but other than that its not really possible to suggest anything about an installation without actually looking at it. If its 40 years old its probably pvc wiring but as i say, cant really say much over the net.

kramer1

the place is gonna get a full rewire one way or the other, just wanna know if its safe to work on as it is until i get the sparks round, be ready for first fix in about three weeks

Bruthal

kramer1 wrote: »

the place is gonna get a full rewire one way or the other, just wanna know if its safe to work on as it is until i get the sparks round, be ready for first fix in about three weeks

Should be ok if it lasted till now when its getting rewired, if i am rewiring a house being renovated id usually setup a temporary socket or 2 through and RCD for other lads near the old board and disconnect everything else.

kramer1

thanks for the help everyone , much appreciated