Tiger loop

[musicspark]

Hi guys

a customer requires bonging upgrading. the oil supply to the boiler is regulated outside the building by a "tiger loop " feed. Two copper plastic covered micro bore pipes then enter the building - both enter the boiler; which one do I bond?

 

[ian932]

I would do both as the direction of the oil flow has no bearing on the electrical side of things.

Tiger loop is a simple flow and return from tank to boiler and what the boiler does not consume goes back to the tank.

 

[Andy™]

as above, you need to bond both

 

[Evans Electric]

Both.

 

[dave2]

Why bond both when they are both connected to the tiger loop which has a metal body and also the oil pump which again is metal?

Incidentally the tiger loop is not a simple flow and return device to the boiler and it certainly does not allow unused oil to flow back to the tank.

Dave2

 

[Andy™]

each pipe is extraneous. so needs bonded. do you only bond water and not gas because they are connected at the boiler?

 

[musicspark]

what principle are we following here? The regs, scientific principles, or common sense?

On one hand, yes there are two pipes on the Tiger Loop, on the other they are joined.

And yes, I suspect that a copper water pipe has a lower resistance than a 10mm bond and they are indeed joined at the boiler -and therefore, in theory, should not need bonded. However belt and braces common sense would tell me that bonding all metal work as it enters the building would cover most potential difference scenarios. Of course the real belt and braces approach would be also supplementary bond at all possible points of contact as well.

Ok, where do you stop, and what do the regs say?

And what defines services bonded at point of entry in the case 0f the Tiger Loop?

PS

I do hope I've stirred up some debate here;\ as earthing in general seems to be one of the seems to be a great bone of contention on this forum, and always makes for interesting debate.

 

[SPECIAL LOCATION]

what principle are we following here? The regs, scientific principles, or common sense?On one hand, yes there are two pipes on the Tiger Loop, on the other they are joined.

And yes, I suspect that a copper water pipe has a lower resistance than a 10mm bond and they are indeed joined at the boiler -and therefore, in theory, should not need bonded. However belt and braces common sense would tell me that bonding all metal work as it enters the building would cover most potential difference scenarios. Of course the real belt and braces approach would be also supplementary bond at all possible points of contact as well.

Ok, where do you stop, and what do the regs say?

And what defines services bonded at point of entry in the case 0f the Tiger Loop?

PS

I do hope I've stirred up some debate here;\ as earthing in general seems to be one of the seems to be a great bone of contention on this forum, and always makes for interesting debate.

Debate???? hmmm that always sound good!Applaud Smiley

ONE QUESTION.....

On this particular installation is the oil pipe actually extraneous? e.g. is it liable to introduce an earth potential.

Consider a typical scenario...

• 10mm copper encapsulated in white plastic,
  
• going under ground in a Plastic duct,
  
• connected at the other end to a plastic oil tank,
  

effectively a "double insulated" bit of pipe connected one end to a metal boiler,

other end a plastic tank.

Where is the earth potential being brought INTO the property?

In this case it would actually be Exporting an Earth potential rather than introducing an earth potential....

Thus NOT extraneous?

 

[dave2]

I agree with special location.

I install and service oil boilers and most of the time the pipe work is run above ground to the boiler so I doubt if it is extraneous. However I always bond the pipe.

I dont think it is any different to say a metal overflow pipe from a cistern or a boiler blow off pipe. Would you bond these?

Dave2

 

[Andy™]

even if its buried underground in plastic and is over 22K ohms, there is a chance in future that this value will drop and make it extraneous. but if it doesnt have any contact with ground (i.e direct from tank to house without touching ground), then its unlikely to be extraneous, and wont need bonded

 

[musicspark]

Debate???? hmmm that always sound good!Applaud SmileyONE QUESTION.....

On this particular installation is the oil pipe actually extraneous? e.g. is it liable to introduce an earth potential.

Consider a typical scenario...

• 10mm copper encapsulated in white plastic,
  
• going under ground in a Plastic duct,
  
• connected at the other end to a plastic oil tank,
  

effectively a "double insulated" bit of pipe connected one end to a metal boiler,

other end a plastic tank.

Where is the earth potential being brought INTO the property?

In this case it would actually be Exporting an Earth potential rather than introducing an earth potential....

Thus NOT extraneous?

Good point Specs, but no it's a metal tank

And, hey Specs, do you really live in a caravan?

 

[musicspark]

Ok you guys I am well aware of the principles of, true earth and local earth but my training did not cover this in great detail - so

"I think therefore I bond!"

Is there a link or site which will give me a more in depth understanding of this and how it affects PME and TT supplies?

or perhaps I should start a new thread about exporting PME

 

[Andy™]

or perhaps I should start a new thread about exporting PME

there are already many threads on the exporting TNCS debate. mostly in 'outside/garage supply' threads

 

[musicspark]

[quote name='Andy

 

[Andy™]

ask away

 

[Apache]

I don't suppose anyone would be too bothered if I re-opened that particular can of worms? Andy?

This is the first big exported earth thread

Here's my confession with much detail!

Read them first. There will be a test @ the end.

 

[musicspark]

Well now, I may get back to you tonight, Andy, but I'm having so much fun on that other thread, it might be tomorrow.

Apache , this is both interesting and funny, thanks for the link mate. Guinness

Anybody mind if make a new post on it?

 

[Apache]

Anybody mind if make a new post on it?

Go for it. Nowt to loose, but won't be the same without Steps :|

 

[musicspark]

Go for it. Nowt to loose, but won't be the same without Steps :|

where is Steptoe , anyway?

 

[Apache]

where is Steptoe , anyway?

Dunno. No sign for 6 months now. He has gone AWOL before.