Proving Your Neutral Electrical Connections

[GB.Kayak]

There appears to be anecdotal evidence from recent threads and the interminable debate regarding BS 7671 Amd 3 and the non-combustible CU thing that Neutral connections are the source of many overheating incidents that in some cases lead to fires. There is nothing currently in BS 7671 or other Codes of Practice that require the integrity of the Line-Neutral circuit to be proven

- What is your experience?

- Do you carry out any tests to ensure that the joints that you produce are always 'sound'?

- Does your experience and 'Mk 1, Self-Calibrating' right or left wrist do the right job every time?

- Will you share your photos of the results of dry joint resistive heating and its aftermath if any?

Discuss!

Research regarding the causes of electrical fires; US source

http://www.interfire.org/features/electric_wiring_faults.asp

 

[frontier219]

Dog 'em up tight and make sure you can't pull them out.

 

[Octopus]

Can you add another option?

"don't understand the question"? lol

 

[GB.Kayak]

Can you add another option?

"don't understand the question"? lol

... I don't know ... just the end user here! ;-) Are you pulling my leg?

 

[Octopus]

... I don't know ... just the end user here! ;-) Are you pulling my leg?

Well.... you could do an R2 + RN BUT if its slightly loose you may not see a different reading to R1 + R2 - but a few weeks down the line you may!!

 

[GB.Kayak]

Well.... you could do an R2 + RN BUT if its slightly loose you may not see a different reading to R1 + R2 - but a few weeks down the line you may!!

So it might show up on an extremely diligent electrical inspection? ... but definitely not on most EIs and definitely on a 'drive-by shooting'!

 

[R G]

The neutral bars that seem to be generic on some boards seem to have very tight threaded screws , so much that I have had to use a large flat driver to get them to tighten , if you use a torque driver it would be useless in this situation , you have to really pull them to check that the screw has properly held the wire , doing an e/loop or Rcd test would not always show the loose neutral, I am in favour of re checking all connections after the board has been in use and like to re check the following day when re wiring etc ...

 

[richy3333]

I always have a good tug, gfor, gfor! I must get out more.

 

[Octopus]

One of the options should be:

"when you have to open a CU do you check all the connections for tightness?"

 

[stevey1983]

Just put a high load on end of circuit and use your thermal camera to check all joints. Job done no need for torque screw drivers or metal consumer units then

 

[telectrix]

tried that. thermal camera on my knee joints showed blue.

 

[stevey1983]

That will be because you got good continuity there

 

[ian.settle1]

Don't think anyone in their right mind would answer the last one.

 

[GB.Kayak]

One of the options should be:

"when you have to open a CU do you check all the connections for tightness?"

M,

Do you?

 

[GB.Kayak]

Don't think anyone in their right mind would answer the last one.

Surely many electrical professionals on here believe that few, if any, who do such courses are 'of sound mind' ...

 

[Des 56]

Couldn't answer the poll because I do the Mark 1 right wrist thing,then I wiggle and jiggle,thats followed by a supplementary self torquing third twist with that Mark wrist thing again

 

[Barry White]

Couldn't answer the poll because I do the Mark 1 right wrist thing,then I wiggle and jiggle,thats followed by a supplementary self torquing third twist with that Mark wrist thing again

me too and noticed that 2 people have voted this way HOW?

 

[Tiny Spark]

Yeah I think option 2 and 3 should be linked together TBH.
Either way rawk that biatch down!

 

[GB.Kayak]

me too and noticed that 2 people have voted this way HOW?

You are allowed to select more than one option ... I believe, at least that is how I set it up! How did you get to see the voting ... I can't!

 

[Barry White]

You are allowed to select more than one option ... I believe, at least that is how I set it up! How did you get to see the voting ... I can't!

only let me do one option!
to see who has voted just left click on any of the scores at the right hand side and all is revealed (did say a public vote)

 

[telectrix]

only let me do one option!
to see who has voted just left click on any of the scores at the right hand side and all is revealed (did say a public vote)

tried that. takes me to photobucket asnd a load of spam.

 

[Barry White]

Thats because you did it on my image thats hosted on photobucket try it on the actual poll results on page 1

 

[Octopus]

M,

Do you?

Yes!!!

 

[acvc]

A good few years ago I read a post on here from a wise old spark who said that, as the last person in the consumer unit, it's you responsibility to make sure EVERY connection is left secure. Since then that's what I've done, admittedly using the self-calibrating wrist method.

 

[Jonspark]

Thermographic surveys help with this problem, but only if the equipment under test is running/energised.

 

[GB.Kayak]

One of the options should be:

"when you have to open a CU do you check all the connections for tightness?"

A good few years ago I read a post on here from a wise old spark who said that, as the last person in the consumer unit, it's you responsibility to make sure EVERY connection is left secure. Since then that's what I've done, admittedly using the self-calibrating wrist method.

Thanks for keeping that wisdom alive ...

M, I just wanted your confirmation that this is what you do ... I did not doubt it for 1 ns!

I have nothing against the self-calibrated wrist of a time-served spark, or a the 17 Day or Electrical Trainee who competently discharges their responsibilities in a professional manner! I have no time for anyone who does not act in a professional manner.

 

[Farmelectrics]

Torque screwdrivers ha ha invested in a set not with my Money lol but even so a good buy been nipping breakers up at work to 2 NM

 

[7029 dave]

Dave tight is good enough trust me.

 

[Deleted member 72666]

Yeah I think option 2 and 3 should be linked together TBH.
Either way rawk that biatch down!

I think the first and last options should be grouped together also.

 

[HandySparks]

If I'm measuring a Zs, I'll usually do the Z(line) at the same time; it's an easy check that there's a decent neutral connection. It's just another button to push on the MFT if you've got three test leads connected already.

(BTW, what's the proper symbol for line impedance?)

 

[GB.Kayak]

If I'm measuring a Zs, I'll usually do the Z(line) at the same time; it's an easy check that there's a decent neutral connection. It's just another button to push on the MFT if you've got three test leads connected already.

(BTW, what's the proper symbol for line impedance?)

Nowt in BS 7671 on the subject of the Line-Neutral impedance ... another sign in my book, that the regulations focus so much on the safety function of an installation so as to leave a gaping hole in the safety of the functional purpose of an installation, to distribute power!

 

[GB.Kayak]

flex_m ... really, you let the side down there, what do they teach on these courses ...

 

[Leesparkykent]

Deleted.

 

[GB.Kayak]

Deleted.

Lee ... deleted ... intrigued!

 

[Leesparkykent]

Lee ... deleted ... intrigued!

I wrote something then edited it a few mins later then it come up I wasn't logged in so I just deleted it as couldn't be bothered to write it out again lol.

 

[GB.Kayak]

I wrote something then edited it a few mins later then it come up I wasn't logged in so I just deleted it as couldn't be bothered to write it out again lol.

LMSO! I get pretty frustrated ... I have lost a number of well penned 'thoughts for the day'. I now copy the text to an iPad note if I get the ominous 'you do not have permission ... ' message!

 

[Octopus]

If I'm measuring a Zs, I'll usually do the Z(line) at the same time; it's an easy check that there's a decent neutral connection. It's just another button to push on the MFT if you've got three test leads connected already.

(BTW, what's the proper symbol for line impedance?)

Does this mean your MFT will allow you to do a Zs without a N connction? My Metrel won't

 

[Des 56]

Does this mean your MFT will allow you to do a Zs without a N connction? My Metrel won't

Never having owned a metrel I ask because it is surprising
3 lead test,neutral and earth leads are shorted what is the outcome ?

 

[Leesparkykent]

LMSO! I get pretty frustrated ... I have lost a number of well penned 'thoughts for the day'. I now copy the text to an iPad note if I get the ominous 'you do not have permission ... ' message!

Lol yes It's very frustrating when it happens, I normally copy and then paste it when I log back in but It didn't seem to work that time.

 

[spark 68]

Does this mean your MFT will allow you to do a Zs without a N connction? My Metrel won't

Cannot comment on the Metrel

My Megger requires the N for the No-trip test (three lead test) on the Hi-current test the N and E leads are connected together (effectively a two lead test), for testing ZP-N the Hi-current test would suffice because this would not trip any RCD.

 

[HandySparks]

Does this mean your MFT will allow you to do a Zs without a N connction? My Metrel won't

Yes, it only requires all three leads for the 'no trip' Zs. The full current Zs and the Z(line) tests only need two leads. However, I usually connect all three leads and do both Zs and Z(line) together.


Edit: Fluke 1652C