Discussion on Testing & Verification of an installation

katie275

Mod note:
Thread split out from here.

Risteard81

2011 wrote: »

As I said, I wouldn't be particularly worried in this instance.

I would. It is non-compliant with the National Wiring Rules and hence the installation is uncertifiable like that. Diagonal tracks with concealed twin and skin outside of earthed containment is not a legitimate wiring method.

Of course doing things properly can be dearer, but those who abide by the Wiring Rules shouldn't be penalised for someone doing cheaper non-compliant work. There is, of course, also the safety aspect which is the reason for the Rule existing.

Risteard81

I'm not sure where your reply has gone to 2011, but the simple fact is that it is not permissible to certify non-compliant work. A Completion Certificate is certifying that the work is compliant with ET101, so certainly certification should only be for fully compliant electrical installation work.

Indeed RECI would insist on non-compliances being rectified.

2011

Risteard81 wrote: »

I'm not sure where your reply has gone to 2011

I think we are both in danger of derailing the thread. You have expressed your view and I have expressed mine.

but the simple fact is that it is not permissible to certify non-compliant work.

Yet it happens.

A Completion Certificate is certifying that the work is compliant with ET101, so certainly certification should only be for fully compliant electrical installation work.

I agree, but in the real world this is not always the case.

Bruthal

Risteard81 wrote: »

Indeed RECI would insist on non-compliances being rectified.

Yes. But contractors are purely interested in money. So wiring a house is completed as fast as possible. Not always by the rec personally, but by under pressure non rec employees. You think they use laser lines to put switch drops etc in? So this perfect system you imagine, is fantasy stuff.

I doubt RECI will disassemble the house.

Bruthal

olestoepoke wrote: »

Not possibly it was a non-sensical post

If you think that was safe to stand on just from a photo, before it was drilled, that is nonsense indeed.

Sent ye a few pointers on the heat genie install setup there. Hopefully that does make sense. Any questions, fire away.

Bruthal

2011 wrote: »

I agree, but in the real world this is not always the case.

Yes, there is no practical way to prove an installation is actually perfectly installed. Testing does`t show non vertical drops, or hidden connectors, or damaged cables in many cases etc.

Risteard81

Bruthal wrote: »

Yes, there is no practical way to prove an installation is actually perfectly installed. Testing does`t show non vertical drops, or hidden connectors, or damaged cables in many cases etc.

That is precisely why inspection is more important than testing. Testing merely supplements the inspection. It is why the process is known as inspection and testing, and not testing and inspection.

Jaklmex

Testing and inspection has a nice ring to it

Maybe they should change it

2011

Risteard81 wrote: »

That is precisely why inspection is more important than testing.

I agree with you that both inspection and testing are very important.
However the point you seem to be missing is that no amount of inspection and testing can guarantee 100% compliance with the regulations in every case. For example some issues can be embedded in concrete, or plaster.

Like it or not the fact is many homes out there that have been certified despite having chases that are not perfectly vertical
I can assure you that if you ask any experienced electrician they will tell you that a great many certified installations deviate from the regulations to some extent (in fact some are dangerous). I have carried out many inspections myself and have seen this first hand.

Jaklmex

Installations could be inspected at different phases

Wouldn't be hard to implement and flag breaches of wiring rules during construction

kramer1

Basically , we need real building control and inspection at multiple points of the job , self certification is nonsense . I say this as a RECI registered contractor. Take it out of our hands , we ll pass the cost on to the client and we can all stop talking ****e.

2011

Jaklmex wrote: »

Installations could be inspected at different phases

This is exactly what is done all across the country on many industrial installations.

Wouldn't be hard to implement and flag breaches of wiring rules during construction

That depends on a number of factors, but mainly the cost complexity of the installation and the budget.

Bruthal

Risteard81 wrote: »

That is precisely why inspection is more important than testing. Testing merely supplements the inspection. It is why the process is known as inspection and testing, and not testing and inspection.

If someone gives you jelly and ice cream, does that mean you can't touch the ice cream until the jelly is gone?

Drifter50

kramer1 wrote: »

Basically , we need real building control and inspection at multiple points of the job , self certification is nonsense . I say this as a RECI registered contractor. Take it out of our hands , we ll pass the cost on to the client and we can all stop talking ****e.

Ha, very good, I like that. I have a PSA licence and I`m sick to death of "customers" looking for something done for nothing. Did a quote on Friday, gave the lad the price and then he says can we do it for cash.
I said no, its got to be certified. Then he says to me " Oh, you`re straight are you" WTF..............

3DataModem

olestoepoke wrote: »

What were they thinking when they installed that light in the closet? Is that an exterior waterproof light? Those wires exposed like that can't be safe.

If it’s in a room with a hot water tank, the lights have to be steamproof apparently. Hot press lights in new builds all seem to be these outdoor lights

Gashmuncher

2011 wrote: »

I agree with you that both inspection and testing are very important.
However the point you seem to be missing is that no amount of inspection and testing can guarantee 100% compliance with the regulations in every case. For example some issues can be embedded in concrete, or plaster.

Like it or not the fact is many homes out there that have been certified despite having chases that are not perfectly vertical
I can assure you that if you ask any experienced electrician they will tell you that a great many certified installations deviate from the regulations to some extent (in fact some are dangerous). I have carried out many inspections myself and have seen this first hand.

There is a fundamental misunderstanding from this poster regarding the purpose of testing. The tests required in Part 6 of the wiring rules are in place (not just in Ireland but all over the world) to highlight potential safety issues within the electrical installation which will easily go unnoticed by both the installing electrician and the end user, The tests are not intended to verify the installation complies with the wiring rules.

Example - Test 1 Verify continuity of Protective Conductors (Earths)
An electrical circuit will work perfectly well and will appear to be entirely normal with a disconnected earth conductor. Only by carrying out the required test will a potential issue be highlighted.

There is a similar logic behind each of the required tests. An installation which does not comply with many of the wiring rules could test perfectly well, this simply confirms there are no underlying electrical issues which will potentially start a fire or electrocute the end user. As apposed to that an installation which appears to comply fully with all the wiring rules could have issues which are extremely dangerous.

Example - Neutral to earth short on lighting circuit will be picked up by an Insulation Resistance test. The circuit will work perfectly well with the fault in place but could start a fire if a secondary fault causes high currents to flow through the 1.5 lighting neutral.

Bruthal

Gashmuncher wrote: »

.

Example - Test 1 Verify continuity of Protective Conductors (Earths)
An electrical circuit will work perfectly well and will appear to be entirely normal with a disconnected earth conductor. Only by carrying out the required test will a potential issue be highlighted.

What test verifies the earth conductor is connected properly?

Gashmuncher

Part 6 of ET 101 2008 4th edition

The following tests shall be carried out where applicable.

Verify contuinity of Protecrive and bonding conductors rule 613.2.1

Quote from the rules
" to verify that protective and bonding conductors are electricaly sound and correctly connected"

Bruthal

Gashmuncher wrote: »

Part 6 of ET 101 2008 4th edition

The following tests shall be carried out where applicable.

Verify contuinity of Protecrive and bonding conductors rule 613.2.1

Quote from the rules
" to verify that protective and bonding conductors are electricaly sound and correctly connected"

Verifying continuity doesn't verify a sound protective conductor. And it's not impossible for hidden connectors to be used somewhere on a circuit. So, the continuity and inspection is not a guarantee. You can only do tests to a practicable level, not to a 100% guarantee level.

2011

Gashmuncher wrote: »

The tests are not intended to verify the installation complies with the wiring rules.

Interesting.....
I would argue that testing is primarily used to identify where an installation deviates from the rules.
But don't take my word for it, look at the very first section of part 6 from the National Rules for Electrical installations:

611 General

611.1

Every installation, including subsequent extensions and additions, shall be inspected and tested during erection as far as is reasonably practicable, and on completion, inspected and tested before being put into service by the user so as to verify as far as is practicable that the requirements of these Rules have been fulfilled.

Edit: Maybe I have misinterpreted your post. My point is that testing and inspection although are important can not be identify every possible deviation from the rules. There is a limit to what can reasonably achieved.

Gashmuncher

Bruthal wrote: »

Verifying continuity doesn't verify a sound protective conductor. And it's not impossible for hidden connectors to be used somewhere on a circuit. So, the continuity and inspection is not a guarantee.

Cable has fixed resistance which is directly Proportanal to the cable size and its length. A competent tester (thin on the ground in Ireland) will pick up on a bad connection. A good connection is no problem and won't change the expected resistance.

Check out page 6 here
https://safeelectric.ie/contractors/wp-content/uploads/sites/2/2018/09/Sept-2018-Newsletter.pdf

Bruthal

2011 wrote: »

The very first section of part 6 from the National Rules for Electrical installations conflicts with your view:



Perhaps you have a "fundamental misunderstanding", not me

Seems to be a serious misunderstanding there alright. Everyone knows a circuit with no protective earth will work fine. Yet they post it like it's a revelation of what the tests are really for.

Bruthal

Gashmuncher wrote: »

Cable has fixed resistance which is directly Proportanal to the cable size and its length. A competent tester (thin on the ground in Ireland) will pick up on a bad connection. A good connection is no problem and won't change the expected resistance.

Check out page 6 here
https://safeelectric.ie/contractors/wp-content/uploads/sites/2/2018/09/Sept-2018-Newsletter.pdf

A single connection just touching won't show any real resistance. Try it and see. Showing cable lengths and resistances is meaningless. Get 100 meters of 1.5t and e. Touch brown and blue together at far end. Test. Now put In connector and test. What will they show? Try it.

The 100 meter cable will have its resistance. The touching copper ends on it will be very low resistance compared to the resistance of the cable. The resistance of the touching ends will be minimally different from the ends being in a connector. Once you start mentioning resistance tables on cable lengths, that suggests you have not tried this out.

A barely touching connection may show. But decent contact but not well connected will show as a pass in many cases.

2011

Gashmuncher wrote: »

Cable has fixed resistance which is directly Proportanal to the cable size and its length.

Fixed?
Would the resistance of a cable vary with temperature?
I think you will find that it does. Not only that but the principle of a conductor changing resistance with temperature is commonly exploited (google resistance thermometer).

If a cable was sized correctly for installation in a conduit but under sized for being directly embedded in insulation is there a test that would identify the method of installation?

A competent tester (thin on the ground in Ireland) will pick up on a bad connection.

Do you think that a competent tester can detect any join on a cable that would not comply with the regulations?
What would you define a "bad connection" as?
Would that just be a connection that is of higher resistance that would be desirable?
Or is it more complicated than that?

I am sure that I could join two conductors together in a way that would provide suitably low resistance but would still be completely unacceptable for mains voltage in an installation.

A good connection is no problem and won't change the expected resistance.

So are you stating that a good connection has no resistance what so ever? Or a good connection has low resistance and a bad connection has high resistance?

Gashmuncher

I am not particularly interested in getting into a tit for tat conversation here.
You are all entitled to your opinions and I am confident in my knowledge
But here goes and using your favourite breaking down the post and answering each point method


Quote:
Would the resistance of a cable vary with temperature?
I think you will find that it does. Not only that but the principle of a conductor changing resistance with temperature is commonly exploited (google resistance thermometer)

It will, but not enough to be detected by electricians testers which only read to two signifigent digits i.e. down to .01 of an ohm.

If a cable was sized correctly for installation in a conduit but under sized for being directly embedded in insulation is there a test that would identify the method of installation?

No


Quote:
A competent tester (thin on the ground in Ireland) will pick up on a bad connection.
Do you think that a competent tester can detect any join on a cable that would not comply with the regulations?


Yes, the only join on a cable which does not comply is a bad joint. There is no regulation which prohibits a good join on a cable. A good tester will identify a bad (high resistance) connection.
Can you quote the regulation which prohibits a good joint on a cable


What would you define a "bad connection" as?
Would that just be a connection that is of higher resistance that would be desirable?
Or is it more complicated than that?

Yes higher resistance but not desirable and it's not more complicated

I am sure that I could join two conductors together in a way that would provide suitably low resistance but would still be completely unacceptable for mains voltage in an installation.

Not correct, once again there is no rule which prohibits a good joint in conductors. Any good low resistance connection is always acceptable


Quote:
A good connection is no problem and won't change the expected resistance.
So are you stating that a good connection has no resistance what so ever?

It has resistance, but not enough to be picked up by a test meter which only reads to two significant digits.

Bruthal

Gashmuncher wrote: »

]

Not correct, once again there is no rule which prohibits a good joint in conductors. Any good low resistance connection is always acceptable

Well as I said, two conductors held together can be a low resistance connection. If it could not, how would switches etc work.

I would have to agree with 2011. It would be easy to create a low resistance link that is not acceptable as a protective conductor connection. I'm surprised you disagree that such a scenario is possible.

A good tester will identify a bad (high resistance) connection.

What value would typically be a high resistance value?

Risteard81

2011 wrote: »

I agree with you that both inspection and testing are very important.
However the point you seem to be missing is that no amount of inspection and testing can guarantee 100% compliance with the regulations in every case. For example some issues can be embedded in concrete, or plaster.

Like it or not the fact is many homes out there that have been certified despite having chases that are not perfectly vertical
I can assure you that if you ask any experienced electrician they will tell you that a great many certified installations deviate from the regulations to some extent (in fact some are dangerous). I have carried out many inspections myself and have seen this first hand.

Verification is required during erection and on completion. So the installer certainly is in a position to inspect throughout the job.

I never suggested that periodic inspection could find all issues - that is why Periodic Inspection Reports are not certificates but reports. To suggest I claimed otherwise is false.

Bruthal

Risteard81 wrote: »

Verification is required during erection and on completion. So the installer certainly is in a position to inspect throughout the job.

Will the installer find one of his own non vertical switch drops, and rectify it upon discovery, after somehow forgetting about his little breach?

gctest50

katie275 wrote: »

.................

When I challenged him about the horizontal chase he said it was because he had to chase that way after performing a metal detection test, still not convinced on that one but it’s done now
............

katie275 wrote: »

.................

after performing a metal detection test,

That'd be the metal telephone socket just above it ?



Did he put "Metal Detection Test" on the invoice ?

One way was remove to the phone socket & its wiring and run the conduit for light switch up in a straightish line vertically like a civilised human

2011

Risteard81 wrote: »

Verification is required during erection and on completion. So the installer certainly is in a position to inspect throughout the job.

Agreed and never disputed.
The point that I and others are making is that a REC is inspecting his own work which is nonsense. This is why so many rules are routinely ignored.

I never suggested that periodic inspection could find all issues - that is why Periodic Inspection Reports are not certificates but reports. To suggest I claimed otherwise is false.

Agreed.
What I am suggesting is that when you stated that a house with a diagonal chase was uncertifiable is balderdash.

The point that we are fundamentally disagreeing that you will not engage on is:
1) Self certification is a nonsense
2) Many installations that are not compliant with the rules are certified.

gctest50

gctest50 wrote: »

One way was remove to the phone socket & its wiring and run the conduit for light switch up in a straightish line vertically like a civilised human

The reason its diagonal at the end is because he reused an old conduit.

Risteard81

2011 wrote: »

Risteard81 wrote: »

Verification is required during erection and on completion. So the installer certainly is in a position to inspect throughout the job.

Agreed and never disputed.
The point that I and others are making is that a REC is inspecting his own work which is nonsense. This is why so many rules are routinely ignored.

I never suggested that periodic inspection could find all issues - that is why Periodic Inspection Reports are not certificates but reports. To suggest I claimed otherwise is false.

Agreed.
What I am suggesting is that when you stated that a house with a diagonal chase was uncertifiable is balderdash.

The point that we are fundamentally disagreeing that you will not engage on is:
1) Self certification is a nonsense
2) Many installations that are not compliant with the rules are certified.

It's not balderdash to state that it is impermissible to certify an installation with Rule breaches. I never suggested that it never happens. It shouldn't though, and people shouldn't pretend that the light switch wiring shown is acceptable.

2011

Risteard81 wrote: »

It's not balderdash to state that it is impermissible to certify an installation with Rule breaches.

Agreed, but that is not what you said.
You specifically said it was “uncertifiable” which means it could not be certified.
Clearly this is not the case.

I never suggested that it never happens.

Then we agree.

It shouldn't though, and people shouldn't pretend that the light switch wiring shown is acceptable.

Yes, I agree.
My point is that although it is not correct and should not be accepted it would not concern me that much. I have seen so many serious issues issues that more minor ones like this are not as big a deal to me.

So it would seem that our points of view are not as far apart as I thought, however I see thy you did not address my point on self certification. Judging by your posts you insist on a high standard of work with attention to detail, surly certification by a third party would be to your advantage? As you now accept that some certified installations are not compliant you must agree that some only get away with this because of self certification?

2011

Gashmuncher wrote: »

It will, but not enough to be detected by electricians testers which only read to two signifigent digits i.e. down to .01 of an ohm.

Then the resistance is not “fixed”. Depending mainly on the length of run, the change in temperature and the CSA of the cable the resistance change by more than 0.1 ohms.

See link: https://www.cirris.com/learning-center/general-testing/special-topics/177-temperature-coefficient-of-copper

There is no regulation which prohibits a good join on a cable.

There are plenty if we take your position that any low resistance joint is a good joint.

A good tester will identify a bad (high resistance) connection.

I disagree. You are putting too much faith in what testing can achieve.
A joint could be bad because it does not have sufficient IP rating, lacks mechanical protection, does not prevent direct contact with live parts, is susceptible to corrosion, puts undue strain on the conductors....... The list goes on.

Can you quote the regulation which prohibits a good joint on a cable

Yes, I think I can when I have the rules in front of me. I will come back to you later on this.

Yes higher resistance but not desirable and it's not more complicated

So if it simply twisted mains voltage wires together and the resistance across the join was low that would be acceptable?

Not correct, once again there is no rule which prohibits a good joint in conductors. Any good low resistance connection is always acceptable

As above low resistance is not the only criteria that a cable joint should be judged on.

It has resistance, but not enough to be picked up by a test meter which only reads to two significant digits.

That is not correct.
Even the test leads have a resistance that standard test meters read. Besides it is not just the resistance of the joint at the time of assessing it that is important it is also how it performs over time. This is why so many other tactoyhave to be considered, see some examples above.

Bruthal

2011 wrote: »

As above low resistance is not the only criteria that a cable joint should be judged on.
.

An example would be bonding straps. The horrific practice of simply clamping the cut earths under the screws rather than using lugs. Massive difference in quality. Not much difference in test results.

Bruthal

2011 wrote: »

.
That is not correct.
Even the test leads have a resistance that standard test meters read. Besides it is not just the resistance of the joint at the time of assessing it that is important it is also how it performs over time. This is why so many other tactoyhave to be considered, see some examples above.

Another example similar to bad connections,

Using the tables G muncher linked to, 1 meter of 1.5 copper is 0.02 ohms. So 1 cm of it is 0.0002 ohms.

So if we ran in 50 meters of 10 square, and part way along the circuit we add in a link of 1.5 square 1 cm long, or pare the 10 square copper down to 1.5 to eliminate connections , it will be a serious reduction in integrity, and similar to a bad connection. But the 2 place ohm meter cant detect it

Even paring it down to 0.5 or even 0.1 square it's still not going to show. But it is now 15 times smaller than 1.5, but it's resistance is still well below the meter resolution.

2011

2011 wrote: »

As you now accept that some certified installations are not compliant you must agree that some only get away with this because of self certification?

From the reluctance to address this question we can all draw our own conclusions.

Risteard81

2011 wrote: »

2011 wrote: »

As you now accept that some certified installations are not compliant you must agree that some only get away with this because of self certification?

From the reluctance to address this question we can all draw our own conclusions.

No reluctance. I'm away for a few days. That's the only reason.

People should only certify compliant work.

2011

Risteard81 wrote: »

No reluctance.

That does not appear to be the case as the question remains unanswered.

It’s a simple question, you either believe that:
A) Self certification should be replaced with third party certification.
Self certification is acceptable.

Personally I believe option A to be the correct answer as there are certified installations that do not comply with the rules as you now accept.

Tuco88

If you know the resistance of 1m of 0.75mm^2 wire thats fine. Its not much good to you when you can only guess the lenght of the cable run, provided you have no connection issues, all your values will vary.

Take a typical control loop, a knife edge terminal barely touching won't show as a bad connection.

Depending on resistance values to prove good connections is not enough imo.

Bruthal

Tuco88 wrote: »

.

Depending on resistance values to prove good connections is not enough imo.

Thats the point I was making. The tables showing resistance values of cables was not really relevant to the fact 2 cables just touching can show low resistance which might not be measurable by a tester compared to a proper connection. A good connection has to stand the test of time.

gctest50

You could load the circuits up to their limits and have a snoop around with a IR camera


Be a extra bit of happiness

2011

I suppose that it all starts with understanding the limitations of what testing can achieve.
This is an area that generates a lot of confusion.

Risteard81

2011 wrote: »

Personally I believe option A to be the correct answer as there are certified installations that do not comply with the rules

This can be dealt with through disciplinary procedures, however.

People shouldn't think it acceptable to certify non-compliant installations. Third-party certification would be no guarantee as to what someone has done either, as defects could be hidden from view.

2011

Risteard81 wrote: »

This can be dealt with through disciplinary procedures, however.

People shouldn't think it acceptable to certify non-compliant installations. Third-party certification would be no guarantee as to what someone has done either, as defects could be hidden from view.

A very weak argument in my opinion, but at least it’s an answer
Obviously some deviations from the rules can be concealed, but many of the most dangerous ones can’t. I don’t know about you but anytime I assess myself I get an A+

My biggest issue with third party certification is the additional cost and inevitable schedule impact for the customer.

Risteard81

2011 wrote: »

A very weak argument in my opinion, but at least it’s an answer
Obviously some deviations from the rules can be concealed, but many of the most dangerous ones can’t. I don’t know about you but anytime I assess myself I get an A+

My biggest issue with third party certification is the additional cost and inevitable schedule impact for the customer.

Well, if you accept that inspection is more important than testing (with testing merely supplementing inspection), then it stands to reason that someone coming along later and simply testing things may well not find what you have done. It is not correct to suggest that dangerous defects cannot pass tests - they can.

Bruthal

Risteard81 wrote: »

Well, if you accept that inspection is more important than testing (with testing merely supplementing inspection), then it stands to reason that someone coming along later and simply testing things may well not find what you have done. It is not correct to suggest that dangerous defects cannot pass tests - they can.

How do you inspect an employee install, trace every circuit along its entire length?

2011

Risteard81 wrote: »

it stands to reason that someone coming along later and simply testing things may well not find what you have done.

Yet inspectors still manage to find issues when they inspect. See the top 10 rule breaches on page 3 here. I would argue that far fewer installations would certified with these breaches if only third party certification was permitted. Obviously a minority of RECs are quite happy to self certify these installations with these breaches in place. God only knows what else is out there that has not been inspected.

It is not correct to suggest that dangerous defects cannot pass tests - they can.

It is also not correct to suggest that I suggested that

There is no perfect solution, but that does not mean that the situation can not be improved.

Risteard81

Bruthal wrote: »

Risteard81 wrote: »

Well, if you accept that inspection is more important than testing (with testing merely supplementing inspection), then it stands to reason that someone coming along later and simply testing things may well not find what you have done. It is not correct to suggest that dangerous defects cannot pass tests - they can.

How do you inspect an employee install, trace every circuit along its entire length?

You supervise it obviously.