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How exactly does earth grounding work in a building


ubonr1971

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We are renovating a building thats 40 yrs old. All old wiring is being ripped out. Have done this for the 3rd and 4th floor and have painted primer on all walls and ceilings. We are now ready to install new wiring on these 2 floors. New 3 prong sockets will be put in with light switches etc. We will re-use the existing electric boxes on each floor which is located above each stair case. 

 

Theres no existing earth (ground) and later a rod will have to be put in the ground / soil. 

 

But my question is.... If a critical electrical problem occurs, for example on the 4th floor, does each floor have to be wired (connected) to the main box on the ground floor which links up to the rod in the soil??

 

On Monday the electrician is coming to do wiring on the 3rd and 4th floor and thus want to know now should he be running wires / connection between the 2 floors. Then when we do the 1st and 2nd floor do we do the same and then do the rod thing in the soil??

 

If someone can explain in easy language it would be appreciated

thanks

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  • 2 weeks later...

each box on each floor should be connected by an earth cable, which in turn, is connected to the earth rodd.

so in other words, you have a continuous route to earth from each floor

I am a qualified UK electrician.

 

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1 minute ago, nickmondo said:

each box on each floor should be connected by an earth cable, which in turn, is connected to the earth rodd.

so in other words, you have a continuous route to earth from each floor

I am a qualified UK electrician.

 

forgot to mention, but of course, in addition to the above, all of your sockets, outlets, need to also have an earth connection to the box.   So in other words, 1st floor, all outlets need to have an earth connected to the box on the 1st floor, 2nd floor same, etc, etc.

I hope you have got some decent consumer units (boxes containing the breakers) with RCD fitted.

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 My question to the experts.

Given the   fast speed that breakers operate at -do you really need an earth

A few years ago I plugged in a brand new water heater

There was an immediate flash and all power in my condo shut down.

The amazing thing was that the breakers in the box in the room all were in the 'ON ' position.

So I have no power in the room but all the power switches showed 'ON'

I contacted the security guard. He opened a large cupboard on the corridor. Then he reset a switch pertaining to my room.

So my Q is given the speed of the breaker in the corridor-is an earth necessary or simply a relic of out of  out date technology

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43 minutes ago, Delight said:

 My question to the experts.

Given the   fast speed that breakers operate at -do you really need an earth

A few years ago I plugged in a brand new water heater

There was an immediate flash and all power in my condo shut down.

The amazing thing was that the breakers in the box in the room all were in the 'ON ' position.

So I have no power in the room but all the power switches showed 'ON'

I contacted the security guard. He opened a large cupboard on the corridor. Then he reset a switch pertaining to my room.

So my Q is given the speed of the breaker in the corridor-is an earth necessary or simply a relic of out of  out date technology

That would most likely be the main breaker that tripped from short circuit to or in your water heater.  
YES - you need earth to send faults that won't trip a breaker to ground and not to you.

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1 hour ago, Delight said:

 My question to the experts.

Given the   fast speed that breakers operate at -do you really need an earth

A few years ago I plugged in a brand new water heater

There was an immediate flash and all power in my condo shut down.

The amazing thing was that the breakers in the box in the room all were in the 'ON ' position.

So I have no power in the room but all the power switches showed 'ON'

I contacted the security guard. He opened a large cupboard on the corridor. Then he reset a switch pertaining to my room.

So my Q is given the speed of the breaker in the corridor-is an earth necessary or simply a relic of out of  out date technology

Since a current that is less than the usual trip (30mA) of an RCBO can kill a reasonable % of children and old or weak individuals if going from hand to hand, and fit healthy people if they fall badly

 

Yes absolutely earthing is required.

ECB61E8E-74A8-436A-9972-E076EA25ADE9.jpeg.848877ec370282ffae9135228a7432c7.jpegD59DC3EA-C802-46EE-8D4D-7127F4AF6BB7.png.6498d2fd2e675a160cf43b8a61feb808.png

Edited by sometimewoodworker
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1 hour ago, Delight said:

 My question to the experts.

Given the   fast speed that breakers operate at -do you really need an earth

A few years ago I plugged in a brand new water heater

There was an immediate flash and all power in my condo shut down.

The amazing thing was that the breakers in the box in the room all were in the 'ON ' position.

So I have no power in the room but all the power switches showed 'ON'

I contacted the security guard. He opened a large cupboard on the corridor. Then he reset a switch pertaining to my room.

So my Q is given the speed of the breaker in the corridor-is an earth necessary or simply a relic of out of  out date technology

in industry we called it 'belt & braces' which means you are not relying on one thing for your safety. breaker contacts can weld closed which means your rcd won't trip plus rcd's can be damaged by someone doing insulation testing (although I've never seen a domestic electrician insulation testing here).

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1 minute ago, sometimewoodworker said:

A few years ago I plugged in a brand new water heater

There was an immediate flash and all power in my condo shut down.

The amazing thing was that the breakers in the box in the room all were in the 'ON ' position.

So I have no power in the room but all the power switches showed 'ON'

Not surprising, as the breakers are protecting the wiring and had no time to react.

 

1 hour ago, Delight said:

I contacted the security guard. He opened a large cupboard on the corridor. Then he reset a switch pertaining to my room.

I assume that you unplugged the heater before the reset.
 

It’s probable that the circuit or appliance was faulty and that the outside switch was an RCBO 

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I have answered similar questions regarding earthing previously, this is no different.

Effective earthing is essential for safety.

From the basement to the attic and every floor inbetween must have earth wiring connected directly to the earth spike.

And for an earth spike (rod) to be effective it must be made of solid copper or copper plated steel, and it must be driven into a part of the ground that remains wet all year round, the leach drains/septic tanks are good locations.

An earth spike in dry clay/sand is as effective as having no earth wire at all.!

Thai electricians are notoriously lax when it comes to earthing.

Insist on effective earthing and earth leakage circuit breakers (residual current safety switches) for your and everyone elses' safety...!

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Apart from your earth/grounding wires n rod why aren’t you replacing the boxes with European quality fuse/ power boxes ?

I hope your installing a European styled breaker switch system on all house circuits and the main input circuit as well.

any home not fitted with state of the art breaker switching is a potential fire and or electrocution trap!

hiw come your electrician isn’t able to sit, advise, and define the wiring throughout the house? It’s the electricians job to know and do this NOT you????

oh and make sure the sparkle splits all the outlets across the circuit board in a balanced way otherwise your gunna have fuse problems (and if you’ve got an ounce of safety sense you will be installing breaker / safety switches which if circuits are over loaded improperly will make your safeties trip regularly).

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2 minutes ago, Tropposurfer said:

Apart from your earth/grounding wires n rod why aren’t you replacing the boxes with European quality fuse/ power boxes ?

I hope your installing a European styled breaker switch system on all house circuits and the main input circuit as well.

Not good advice.  This is not the UK and fused outlets are not needed or required here.

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3 minutes ago, MadMuhammad said:

sorry, are you saying bare minimum standards are all that is required or have I missed the point?

Not at all. I'm saying fused outlets are for ring circuits and the UK is the only place that has them. 

 

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1 hour ago, bankruatsteve said:
1 hour ago, MadMuhammad said:

sorry, are you saying bare minimum standards are all that is required or have I missed the point?

Not at all. I'm saying fused outlets are for ring circuits and the UK is the only place that has them. 

I think I’m missing something here. 
 

Apart from in the CU the U.K. doesn’t have fused outlets, fused plugs yes, but not fused sockets.
 

Fused (or MCB) protected circuits both ring and radials sure.
 

Switched sockets are common in the U.K. but I’ve never seen a fused socket in use anywhere.

Edited by sometimewoodworker
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23 minutes ago, sometimewoodworker said:

I think I’m missing something here. 
 

Apart from in the CU the U.K. doesn’t have fused outlets, fused plugs yes, but not fused sockets.
 

Fused (or MCB) protected circuits both ring and radials sure.
 

Switched sockets are common in the U.K. but I’ve never seen a fused socket in use anywhere.

My mistake then.  I thought the sockets/receptacle were fused.  Anyway... it's only done in ring circuits in the UK.  Wait... why would the plug be fused?

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34 minutes ago, bankruatsteve said:

My mistake then.  I thought the sockets/receptacle were fused.  Anyway... it's only done in ring circuits in the UK.  Wait... why would the plug be fused?

Because it is safer. The ring main is normally 30A. Individual fused plugs are usually anything from 2A, 3A, 5A and 13A so a bedside lamp would have a 2A fuse and a kettle 13A.

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34 minutes ago, Mises said:

Because it is safer. The ring main is normally 30A. Individual fused plugs are usually anything from 2A, 3A, 5A and 13A so a bedside lamp would have a 2A fuse and a kettle 13A.

Safer?  Hmm.  So, if you buy a product in the UK, it has a fused plug on it?  Wow.

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4 hours ago, bankruatsteve said:

My mistake then.  I thought the sockets/receptacle were fused.  Anyway... it's only done in ring circuits in the UK.  Wait... why would the plug be fused?

I have found fused sockets available on screwfix, however in 40 years I have never seen one in use.
 

Ring final circuits are seldom installed today due to the interesting ways they can fail and the fact that if you split the ring into 2 radials you gain at least 10 A capacity.

 

You can not purchase anything with a compliant plug on it that does not have a fuse. The standard compliant fuses are all sand filled ceramic bodied and the 4 common sizes are 3A, 5A, 10A and 13A with 13A being the maximum. It is also difficult to impossible to bridge the line and neutral pins when the plug is partly pushed home (as they are sleeved), a trick that is all too easy to do, DAMHIKT, with Thai, US and many other plugs

 

09173607-6B9A-45D1-A883-771F2F480DA9.jpeg.4adc63177a6d862a59b0a25b4582e5c8.jpeg

 

as you can see this has a 13A fuse
D18F8AD5-F53D-448C-9B09-5E38DFABC53B.jpeg.40ee8fbc4d55d6752336423c56b35e42.jpeg
 

 

sleved line and neutral unsleved earthDEDE86E0-6F7A-4C40-8577-FE0833516AF3.jpeg.8b56c73bf019e3a573f305f56f3a7c95.jpeg

Edited by sometimewoodworker
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2 hours ago, bankruatsteve said:

Safer?  Hmm.  So, if you buy a product in the UK, it has a fused plug on it?  Wow.

Yes, electrical devices cannot be sold in the UK without a fitted fused plug.  And, of course the fuse has to be the correct rating for the device.

 

There are downsides to all this though.  Even if you have a degree in electrical engineering or, in my case, the ability to wire a 3 phase industrial unit safely through experience, it is illegal to fit in your own home an extra socket on a spur off the ring main unless you have a stupid piece of paper from some electrical federation or whatever. It's the same as the legal and medical profession protecting their monopoly.

 

The ultimate stupidity in the UK is PAT testing (Google it) whereby in a commercial environment you have to pay once a year an approved person £2-5 to plug, say your phone charger, with its plastic earth pin in a testing device to record any earth leakage. Well guess what, the result will be zero and the approved guy sticks a sticker on the plug and plans his next holiday to the caribbean because he can do 30-60 an hour, Dito double insulated electrical appliances.

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19 minutes ago, Mises said:

There are downsides to all this though.  Even if you have a degree in electrical engineering or, in my case, the ability to wire a 3 phase industrial unit safely through experience, it is illegal to fit in your own home an extra socket on a spur off the ring main unless you have a stupid piece of paper from some electrical federation or whatever.

That is rather disingenuous. It is perfectly legal to do work on your own home.

the kicker though is that If you aren’t registered to self certify you need 

Quote

B.Third-party certification by a registered third-party certifier.

c. Certification by a building control body.

You can also choose not to bother with a certificate but then your house insurance may not be valid and you cannot sell the house.

 

But it is not illegal.

 

Absolutely the piece of paper you have to get to self certify is ridiculous. But the claimed intent (reduction in cowboy work) is good and probably means that Joe Blogs who comes to fit a new circuit and has that paper, does know enough not to kill you. 

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17 hours ago, millymoopoo said:

I have answered similar questions regarding earthing previously, this is no different.

Effective earthing is essential for safety.

From the basement to the attic and every floor inbetween must have earth wiring connected directly to the earth spike.

And for an earth spike (rod) to be effective it must be made of solid copper or copper plated steel, and it must be driven into a part of the ground that remains wet all year round, the leach drains/septic tanks are good locations.

An earth spike in dry clay/sand is as effective as having no earth wire at all.!

Thai electricians are notoriously lax when it comes to earthing.

Insist on effective earthing and earth leakage circuit breakers (residual current safety switches) for your and everyone elses' safety...!

Totally agree with you. The placing of an earth rod, resistance, should be measured.

Only then the rod can do its work properly. If not then you are in danger again.

Depending on soil(moist) to place rod in, you need to get deeper, until resistance is real low.

 

Ive seen the rods, metal/copper plated. Its cheaper and they are about 1.5 meters each.

Maybe you need 10 of them or even 20. You need to measure.

See movies on youtube about grounding. For instance this one: 

They show measuring in several ways.

 

However being coated metal , the rod can corrode in time and you loose the ground.

Better to use all copper rods, it lasts longer and so your safety.

To be more safer , wise to use RCBO's.

A difference of 30 mA between live and neutral, shuts down the power.

It means you have a power leak.

 

Even then you could die. It all depends on time you are exposed to 30 mA and what is the situation.

Your body is salty, you sweat, skin condition, you stand on an isolator (shoe) or in water and of course your heart condition.

Under estimating electrical power could cost lives in a jiffy. Beware. 

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9 hours ago, sometimewoodworker said:

That is rather disingenuous. It is perfectly legal to do work on your own home.

the kicker though is that If you aren’t registered to self certify you need 

You can also choose not to bother with a certificate but then your house insurance may not be valid and you cannot sell the house.

 

But it is not illegal.

 

Absolutely the piece of paper you have to get to self certify is ridiculous. But the claimed intent (reduction in cowboy work) is good and probably means that Joe Blogs who comes to fit a new circuit and has that paper, does know enough not to kill you. 

So use an extension cable instead.

 

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