Running Earth Wire from Fuseboard to Boilerhouse.

Bruthal

danjo-xx wrote: »

I reckon fitting an earth rod at boilerhouse would cost a lot more than running a cable around the house or would it. Someone said running a cable could take a days work


There will be no gas mains entering the house.

Fitting an independant earth rod won't bond anything.

mikeyjames9

what's the need for a main bond then if this gas service pipe is plastic?

Sir Arthur Daley

mikeyjames9 wrote: »

what's the need for a main bond then if this gas service pipe is plastic?

Pe pipe is not permitted indoors.

Robbie.G

wouldnt the gas line be going underground from house to boiler house and is it only pe pipe permitted for this? open to correction.[/quote]

The service line can be copper or GB also

shane 007

Underground gas pipe can be PE, plastic coated/wrapped copper or wrapped galvanised GB.

If there are electrical services being buried with the gas pipe, there would have to be a minimum separation distance of 300mm.

mikeyjames9 wrote: »

what's the need for a main bond then if this gas service pipe is plastic?

Once the PE surfaces externally, it will be protected by a GRP sleeve & transitioned to copper or galvanised GB. This would then have to be bonded.

Sir Arthur Daley

Robbie.G wrote: »

The service line can be copper or GB also

If you had a situation where all the gas line was metallic are the gas regs satisfied if one bonds it say in the house even though gas boiler is in external boiler house?

shane 007

Sir Arthur Daley wrote: »

If you had a situation where all the gas line was metallic are the gas regs satisfied if one bonds it say in the house even though gas boiler is in external boiler house?

It would. There are 3 locations as to where to bond the gas pipe; within 500mm of the gas meter but not within the meter box, at the point of entry to the building or where the gas pipe becomes first visible within the property.

Obviously, if there was PE used between the meter & the property, bonding at the meter would be pointless & one of the latter 2 locations would have to be used.

.G.

Amazing how people can get so passionate about main bonding that they abuse people!

danjo-xx

.

danjo-xx

1. Anyone know if wiring regulations permit a 10sq earth cable be run, along roof joists or ridge board or must cable be kept at ceiling joists level, in case roof blows off or something:D

2. Does it need to be run thru conduit in attic.

Have a sparks doin it want to make sure he does it right.

Robbie.G

danjo-xx wrote: »

1. Anyone know if wiring regulations permit a 10sq earth cable be run, along roof joists or ridge board or must cable be kept at ceiling joists level, in case roof blows off or something:D

2. Does it need to be run thru conduit in attic.

Have a sparks doin it want to make sure he does it right.

Cable canbe clipped at high level alright.
It should be mechanically protected if under 1.5mtrs.
If your mans a sparks he should know this

danjo-xx

When sparks does the job should I be given a cert or just a receipt.

danjo-xx

Robbie.G wrote: »

Cable canbe clipped at high level alright.
It should be mechanically protected if under 1.5mtrs.
If your mans a sparks he should know this

Have you any source for this, I've had several 'Registered' sparks out and they laughed at me when I mentioned this.

mikeyjames9

danjo-xx wrote: »

Have you any source for this, I've had several 'Registered' sparks out and they laughed at me when I mentioned this.

i've never heard of it anyhow and i'm reasonably familiar with ET101:2008

2011

danjo-xx wrote: »

Have you any source for this, I've had several 'Registered' sparks out and they laughed at me when I mentioned this.

"Registered" means that they paid some money to join a "club"
It does not make them superior electricians.

What Robbie.G is referring to is a rule of thumb or good practice.
This would have materialised from a number of places in ET101:2008 including:

● 132.5 External influences

The design of the electrical installation shall take into account the extremal influences to which it will be subjected.

● 133.3 Conditions of installation
Electrical equipment shall be selected so as to withstand safely the external influences characteristic of its location to which it may be exposed. If, however, an item of equipment does not have by design the properties corresponding to its location, it may be used on condition that adequate additional protection is provided as part of the completed electrical installation.

● 5226.1 Wiring systems shall be selected and erected so as to avoid damage arising from mechanical stress due to impact, penetration or compression during installation, use and maintenance.

Robbie.G

danjo-xx wrote: »

Have you any source for this, I've had several 'Registered' sparks out and they laughed at me when I mentioned this.

It might not be a specific rule but that's the way I was taught good working practice.And if a "reg " spark doesn't know what I meant then that's their loss.
If I was running a cable I would always duct/conduit under 1.5 mtrs even higher but I'm old school

danjo-xx

2011 wrote: »

"Registered" means that they paid some money to join a "club"
It does not make them superior electricians.

If the consumer can't trust a 'Registered' sparks then where the hell does that leave the ordinary Joe Soap:rolleyes:

2011

danjo-xx wrote: »

If the consumer can't trust a 'Registered' sparks then where the hell does that leave the ordinary Joe Soap:rolleyes:

Unfortunately time and time again it has been shown that customers can't trust registered electricians, there are a few cowboys out there.
However this is not my point.

I am not suggesting that there is not a role for registered electrical contractors (I was a REC many years ago myself), clearly there is.
My point is that by when an electrician becomes registered it does not somehow make them a better or more knowledgeable electrician.

roy rodgers

a couple of question I would like to clarify.

if you cant get a 10 sq earth to the gas line or boiler house can a new rod be installed and bonded from there??

if you can get the bonding at the meter say, and that pipe ran to the boiler in copper and also to the hot press. is it ok to cross bond it at the boiler then???

Zimmerframe

danjo-xx wrote: »

If the consumer can't trust a 'Registered' sparks then where the hell does that leave the ordinary Joe Soap:rolleyes:

Often they are the same person.

mikeyjames9

roy rodgers wrote: »

a couple of question I would like to clarify.

if you cant get a 10 sq earth to the gas line or boiler house can a new rod be installed and bonded from there??

if you can get the bonding at the meter say, and that pipe ran to the boiler in copper and also to the hot press. is it ok to cross bond it at the boiler then???

your first question ;no
main bonding conductors connect to main distribution board

your second question; no

you cant loop main bonding in copper pipe
it can be looped to other services in unbroken copper cable

roy rodgers

mikeyjames9 wrote: »

your first question ;no
main bonding conductors connect to main distribution board

your second question; no

you cant loop main bonding in copper pipe
it can be looped to other services in unbroken copper cable

thanks mickeyj
I cant understand why a new rode cant be installed to bond a gas line or heating system only.. you see im a plumber and do a lot of seai work and all im looking for is to get the heating job up to seai standard...

now some jobs I have went too wouldn't have room for a 10sq earth and the cable going to the rod would only be 2.5 or something. so I always reckoned sinking a new 10sq would be a better job for the heating..

on the second question if your cross bonding on copper piping is that aloud either it being gas or water??

2011

I am no authority on earthing, but from what I have seen on large eclectical installations (>1MW) fed from a common source:
The main earth bar located in the main LV distribution board is fed from the main earth pit. The main bar in turn feeds multiple earth bars throughout the installation (including in separate buildings). These earth bars are used primarily for bonding equipment local to each earth bar. Where practical these earth bars are then connected to local earth electrodes.

---

Let's assume that in this case the shed is 100m from the house.
Suppose if a 10 sq. mm bonding conductor was taken from the MET and run to the shed and used to bond various bits conductive parts, these pieces of equipment would now be at the same potential as the MET. There is now a possibility that there would be a potential difference between these metal parts and the ground. This because the MET is tied to a different point of reference, an earth rod 100m away. So theoretically a person touching this metalwork could receive a shock.

In this case I think that there is a good argument to treat it like the industrial installation described above. Why not connect the 10 sq. earth to a local earth bar in the shed? All conductive parts could be cross bonded and connected back to this earth bar which in turn could be connected to a local earth electrode.

Not a very likely scenario for most homes and I guess a 10 sq.mm would be too small a bonding conductor for a shed that far away, just thinking aloud

Sir Arthur Daley

Earthing is a topic that people will always carry different views, say for example a standard bungalow cast iron bath which has been bonded isnt there is now a possibility that there would be a potential difference between these metal parts and the ground.
Theoretically can a person touching this metalwork receive a shock?

Bruthal

roy rodgers wrote: »

thanks mickeyj
I cant understand why a new rode cant be installed to bond a gas line or heating system only.. you see im a plumber and do a lot of seai work and all im looking for is to get the heating job up to seai standard...

It's because a second separate earth rod will not bond metal it's connected to, to other metal within the installation.

Earth rods do not "lock" items connected to them, to earth or 0 volts.

Bonding different items to each other and connecting to a central common earth bar does keep all bonded items at equal voltage or potential though. Bonding is not to keep everything at earth 0 volts, although it attempts to, and does in a properly working setup. But it's main function is to keep everything at equal voltage in the event of faults, a failed neutral upstream of the neutralising point being one major example of where bonding is important.

mikeyjames9

2011 wrote: »

I am no authority on earthing, but from what I have seen on large eclectical installations (>1MW) fed from a common source:
The main earth bar located in the main LV distribution board is fed from the main earth pit. The main bar in turn feeds multiple earth bars throughout the installation (including in separate buildings). These earth bars are used primarily for bonding equipment local to each earth bar. Where practical these earth bars are then connected to local earth electrodes.

---

Let's assume that in this case the shed is 100m from the house.
Suppose if a 10 sq. mm bonding conductor was taken from the MET and run to the shed and used to bond various bits conductive parts, these pieces of equipment would now be at the same potential as the MET. There is now a possibility that there would be a potential difference between these metal parts and the ground. This because the MET is tied to a different point of reference, an earth rod 100m away. So theoretically a person touching this metalwork could receive a shock.

In this case I think that there is a good argument to treat it like the industrial installation described above. Why not connect the 10 sq. earth to a local earth bar in the shed? All conductive parts could be cross bonded and connected back to this earth bar which in turn could be connected to a local earth electrode.

Not a very likely scenario for most homes and I guess a 10 sq.mm would be too small a bonding conductor for a shed that far away, just thinking aloud

I think the earth on the submain to outbuildings where there's extraneous metalwork has to be at least same size as main bonds in the main building(bigger for longer runs)

is it a maximum of 70mm anyhow?

it's to do with the magnitude of possible fault currents on this cable connected to extraneous metalwork i believe

Bruthal

mikeyjames9 wrote: »

I think the earth on the submain to outbuildings where there's extraneous metalwork has to be at least same size as main bonds in the main building(bigger for longer runs)

is it a maximum of 70mm anyhow?

it's to do with the magnitude of possible fault currents on this cable connected to extraneous metalwork i believe

When you look at 10 square to domestic earth rods, doesn't really need to be that size for electrical reasons. But it does make it mechanicaly strong at least. That's a separate opinion to your point though.

2011

Many people do not realise that the resistance to earth through an earth electrode is quite high, generally between 100 & 200 Ohms. This value depends on a number of factors including the resistivity of the soil and length of the rod itself.

Neutralised installations:
In the event of an earth fault once the fault current reaches the neutralising point most of this current will return to the star point of the transformer through the neutral as this is a far lower impedance than down the earth rod and through the ground.

Bruthal

2011 wrote: »

Many people do not realise that the resistance to earth through an earth electrode is quite high, generally between 100 & 200 Ohms. This value depends on a number of factors including the resistivity of the soil and length of the rod itself.

Neutralised installations:
In the event of an earth fault once the fault current reaches the neutralising point most of this current will return to the star point of the transformer through the neutral as this is a far lower impedance than down the earth rod and through the ground.

Yes many assume it's a low impedance path, probably brought about by the teaching, and fact, that a path through earth can be very low impedance due to it's massive cross sectional area. What can be forgotten though, is that earth material is high impedance when the csa is small. And the earth rod only makes a small area connection compared to the area that is required for low impedance.

The earth rod at a neutralized installation is one of many, all connected together from the transformer. As a group, they ensure the neutral is well connected to ground. The more installations connected from the transformer, the more neutral conductor there is, the more earth rods to connect the neutral to earth.