BEMTs

Chr!s · Feb 23, 2011

Why would you require to disconnect bonds individually?

as far as i am aware theres no requirement to disconnect structural bonding

Engineer54 · Feb 23, 2011

Hmmmmm.....!! Perhaps we should weld all these bonds together and have done with it then!! Makes you wonder why we have connectible earth bars, and why some of the bigger one's have multiple removable isolation links, perhaps we ought to weld them up too!!!!

Deleted member 26818 · Feb 23, 2011

You could weld the bonds together, I believe that is an acceptable methode as per BS7430.
I thought the purpose of those removable links was to measure Ze without having to remove the bonds individually.

Engineer54 · Feb 23, 2011

Not as far as i'm aware , when the bonds are coming from different building services. Multiple removable link sections on earthing bars are not there ''Just'' for measuring Ze!!! ...You would only require one removable link if that was the sole purpose..

What are you saying here in answer to a question on another thread on bonding conductors? Am i missing something along the line? ...It is a bit late over here...lol!!!

b) The purpose of this test, is to ensure that the conductors are continuous, to that end they will have to be disconnected at each end so as there are no parallel paths.

Chr!s · Feb 24, 2011

Hmmmmm.....!! Perhaps we should weld all these bonds together and have done with it then!! Makes you wonder why we have connectible earth bars, and why some of the bigger one's have multiple removable isolation links, perhaps we ought to weld them up too!!!!

No need, you just carry out tests to ensure continuity.

A distribution board mounted next to a RSJ, it is acceptable to connect the RSJ to the met and use the RSJ as a bonding conductor, you may connect extraneous conductive parts to that RSJ further down in the location, providing the RSJ meets the requirements of bs7671.

Not sure where your issue lies.

ian.settle1 · Feb 24, 2011

johnboy6083 said:
building earth marshalling terminal

WTF that? is it a new term that is coming out in the 1st amendment

Deleted member 26818 · Feb 24, 2011

No it's quite an old term.

Engineer54 · Feb 24, 2011

Chr!s;237882[B said:
]No need, you just carry out tests to ensure continuity.
[/B]
A distribution board mounted next to a RSJ, it is acceptable to connect the RSJ to the met and use the RSJ as a bonding conductor, you may connect extraneous conductive parts to that RSJ further down in the location, providing the RSJ meets the requirements of bs7671.

Not sure where your issue lies.

So you would have maybe main water and gas main supply, along with other bondable building services connected to an RSJ scattered along it's length?? Not on any project i was involved with you wouldn't!!! What's that all about, ....hunt for/find the the bond connection, ...oh it's somewhere up there, along that RSJ mate, .....Bloody Ridiculous!!!

Oh and how are you going to know those test are confirming continuity?? Very difficult at the best of times, in steel frame buildings that are made up almost exclusively from steel/metalwork!!

Chr!s · Feb 24, 2011

So you would have maybe main water and gas main supply, along with other bondable building services connected to an RSJ scattered along it's length?? Not on any project i was involved with you wouldn't!!! What's that all about, ....hunt for/find the the bond connection, ...oh it's somewhere up there, along that RSJ mate, .....Bloody Ridiculous!!!

Each to their own, im not saying it would be the method i would employ,in some scenarios it may be the most appropriate way, but to say NO as you did is incorrect, extraneous conductive parts may be used as a bonding conductor, fact.

Oh and how are you going to know those test are confirming continuity?? Very difficult at the best of times, in steel frame buildings that are made up almost exclusively from steel/metalwork!!

How do you think?

Engineer54 · Feb 24, 2011

As i stated, .....NOT on any project i was involved with you wouldn't!!! and you can take that to the bank!! lol!!

Not without disconnecting them first, Which was my point from the very start!!!

Chr!s · Feb 24, 2011

As i stated, .....NOT on any project i was involved with you wouldn't!!! and you can take that to the bank!! lol!!

That opinion is a little emphatic., As i stated, it comply s with BS 7671, theres more than one way to skin a cat.

Not without disconnecting them first, Which was my point from the very start!!!

You need to prove continuity, providing the continuity is ok wheres the problem?

Engineer54 · Feb 24, 2011

Sorry Chris, ...not going any further with this thread, it's just going round in circles now. Too many what Ifs and what abouts!! lol!!
There are quite a few anomalies and contradictions in BS 7671 past and present, that many pounce on to make a point.

The real point on this particular matter is that any bonding cable at either EMTs or METs should be disconnectable for testing purposes. Whether they will ever be tested in the future, is another argument....

Chr!s · Feb 24, 2011

The real point is on this particular matter is that any bonding cable at either EMTs or METs should be disconnectable for testing purposes. Whether they will ever be tested in the future, is another argument.

There would be a cable at both the met and emt for disconnection, these would be connected to the structural steelwork which is being used as a bonding conductor.