Is it acceptable to enter low IR on MWC

[FreeLec]

When doing minor works on a circuit, which may take a very short time to complete and it requires a MWC the IR test between L-N and E may be zero due to other electronic items.
You can end up spending 10 times longer looking for and disconnecting them just to get a good IR reading.

The company I work for has a policy of entering the low reading with an explanation of why and then arranging extra time at another time and charging to diagnose and rectify, even if it just means tracing electronic items, disconnecting and re-testing.

This is acceptable to the establishments they are working for.

However, it does not seem correct to enter what is effectively a fault on a certificate that is supposed to show the circuit as tested and okay, just as with an EIC. It's not a EICR so I would have thought this wrong.

However, what other way of doing it is there short of saying to the customer that before any work is done the circuit has to be tested as to fitness and any faults rectified but it's done the other way round with this lot ending up with a fault on the MWC. Only when the fault is cleared (or found that it is just electronic items) is the MWC changed.
The one with the fault is still given to the client until the updated one is done.

There are times, though, when no one has gone back to re-test as the client has given no further instruction, so the client has ended up with a MWC with an IR fault.

Any thoughts?

 

[Midwest]

Midwest

I only mentioned RCBOs as an example of a device that causes a problem on IR to earth. (However, I have seen sparks test with both L and N still in terminals and then fail the circuit).
I test from the DB with both L and N disconnected from the MCB/RCBO/Neutral bar.

The minor works I have explained just above. (This problem I am having is only with this particular job. On other jobs I am doing one thing at a time and can properly test the circuit, but on this it's a nightmare. Working where there are schoolkids you have to take so many precautions and this adds more time. Then there are access problems. It once took me all day to do a 2 hour job there because I had to have access to 3 rooms and 2 corridors. When I could get into one I then couldn't get into the other. I needed to go from one to the other and back. Worked on occupied offices before but it's the first time I've had to work like this.)

I only do small domestic work, so can't comment on what you and Lucien were chatting about.

As you know, you can't do an IR test with rcbo still connected, as it will effect the result, unless you make allowances for the rcbo resistances.


Tin hat on, some might say, that should you be carrying out all the tests prescribed by BS7671, when replacing luminaires for example, hence my question of type of work being done. I also suppose it will depend on what said in the spec for the job you are doing here, as its in a school. Council might specify exactly what it wants done in terms of testing, which your employer has quoted for. Can't see any point doing IR tests, if the circuit in question has not be isolated from accessories that will effect the results of the test.

Have you been given guidance by your employer, and spoke to them of your concerns. If they are telling you to something in a particular way, you'll have to follow their instructions. If your uncomfortable with that, you'll need to find a new employer.

 

[FreeLec]

Aahh! This forum drives me mad. It logs you out while you are typing a reply.

Anyway

The guidance is test Zs to make sure there is and earth. Report IR result as is. This gets reported to the client. The client orders remedials that may involve finding and rectifying a fault or just disconnecting equipment to get an acceptable IR. That's it. Sometimes I hear nothing further and nothing further happens but that is the client and my employers responsibility, not mine.
Personally I think it's not right to give a completion certificate with faults.
I don't have a problem if they want to work that way. It's by pre-arrangement with the client due to the nature of the establishment.
I just posted this to see what others think.
By doing that it led on to what others and Lucian has said causing me to look further and deeper into the types of equipment.
Whenever there is low IR every electrician I have worked with has run around unplugging everything but according to Lucian this may be going over the top. So although not part of the original post about MWC it is still sort of related and very relevant.

 

[HappyHippyDad]

Thanks Lucian.


Here is a comment from someone who replied to the same issue on another forum.
"Nearly every circuit I test has low IR, that is until I unplug the surge protection extension. Another useless invention causing problems".

.

I have just had the same problem testing L/N - E on an IR test, I cant remember the reading but I know it was quite abit <1MΩ (I think around 0.2 or even 0.02MΩ) but this was tested at 500V, tested at 250V it was approx 200MΩ? My mind is a little hazy so results may not be accurate but I'm sure it was something along these lines. This was on a surge protected extension lead.

 

[FreeLec]

That makes complete sense as to the way the surge protector works.

Now that, without a doubt, is due to the component dealing with the surge. At 250V it would not conduct but at 500V it would.
I have found that some surge protectors only have components between L and N so 500V will have no problem with them.

The issue is more to do with other equipment.

 

[Octopus]

DAVESPARKS

I have just noticed your stupid and ignorant comment.

If I was not competent I would not know that something was not right.
I already said that I did not feel happy about the way I am being asked to work.
I am being told to work that way.
I am installing about 50 bulkhead emergency lights next to existing failed integrated fittings.
It is in a school where I have to drag tools, materials, rubble bags, vacuum cleaner, etc between 14 different buildings and back to the same ones as different rooms are being used at different times.
I have to get each one done as quickly as possible within the allocated time.
I have not been given time to disconnect any item of equipment not allowing an acceptable IR result.
I've been told to put a failed IR on the MWC with a comment about why the result is likely + further investigation required.

Maybe you should think it bit more and read the post properly before you make nasty comments.

I also see you thanked Murdoch for making the sarcastic comment of money making con.
If both you and he read the post properly you would both have seen that I said this is pre-arranged with the client. How can it be a money making con if the client has agreed that if something can't be done within an allocated time then a return visit has to be arranged and the initial charge is only for the first allocated time period. They have agreed this.

But it is a money making con..... your company provide a quote to do a job, your company provide an unsatisfactory IR reading on a MWC, so you go back and charge more...... rather than quote to do it properly the first time round...

 

[ipf]

But it is a money making con..... your company provide a quote to do a job, your company provide an unsatisfactory IR reading on a MWC, so you go back and charge more...... rather than quote to do it properly the first time round...

First con I've ever come across where it's agreed with the client to con him..:wink5:

 

[FreeLec]

Murdoch

I can't see what you don't understand about this.

The client is quoted for the job with the understanding that it will take a set amount of time to complete.
The quote takes no account of any other remiedials that may need to be done.
If the remedials take a short time they are done then and there with no extra charge.
If the remedials will involve more than has been quoted for they are informed of such.
They then order those remedials to be done fully expecting to be charged for the extra time.
This has already be pre-arranged with these particular clients. I'm not saying this is the case will all clients but because of the nature of the establishment and the disruption it causes this is what they have agreed and arranged.

Now, where is the con in that?

 

[Plonker 3]

There should be no remedials, the job should be surveyed and priced accordingly before hand. Filling out a EIC with unacceptable results isnt something that should be done on a job. Any discrepancies should should be sorted before any works are carried out.

Besides you are potentially leaving a install that doesnt comply with the BYB. Just because the customer agrees it is acceptable doesnt men that it is OK does it? What if you Zs values were to high but the customer said thats fine sort it out later would you think thats acceptable?

 

[FreeLec]

Dillib

I absolutely agree with what you are saying.
That's why I am trying to sort out the issue with what sort of items cause problems with IR testing rather than end up going to everything and disconnecting etc. This takes up so much time causing comments like "why is it taking so long" and "why have you only done so few" etc.
I presume you have read the whole post and seen the conversation with Lucian.
If I can get an IR result of at least 1 Meg then officially I can continue. However, this is still far too low and leaves no room for further deterioration of IR and still needs to be investigated. I don't know why I have been getting results below 1 Meg. All I know is to get an acceptable result I have to disconnect everything so something isn't right, but not with the wiring. That's why I'm going to be investigating what's going on but it will take a while. Hopefully, I will be able to do that withing this week.

As I've said I don't like working like this but nothing is surveyed beforehand. It is done there and then at the time when the job is going to be done.

I don't install if there is a problem.

For example, on Friday, when identifying the circuit that an integrated emergnecy light is on, I found that the switch line feed was from 3L3 and the permanent feed was from 6L3.
I reported it, then moved on to the next one.

I have had comments from other forums and from sparks I work with that you only need to test the part of the circuit that you are extending but I have already said that I don't agree with this and it should be the whole circuit. This shows the pressure put on sparks to get the job done.

However, the fact that I have posted this in the first place surely shows that I am not happy with the current situation and I am trying to do something about it.

 

[TJ Anderson]

Hi Freelec. Very interesting points and I understand where you are coming from regarding time restraints in real world sparking. A sensible approach would be to write in the Limitations Box "IR of new wiring only". Before someone shoots me down, don't bother. You are the qualified spark, you can put whatever limitations you want on your cert as long as client agrees (I do).

 

[FreeLec]

I'm not sure you can just agree with the client what is acceptable in the cert. After all, it's not a condition report. It is supposed to be saying that everything that has been involved in the minor works is inspected, tested and safe. Therefore the circuit that the new works is involved in must be safe to add to or alter.
So many different views on this.

But at least you can see where I'm coming from.

 

[TJ Anderson]

It is not ideal, but what else can you do if you are not testing prior to extending circuit. As you know, you should not if you cannot confirm circuit is compliant to extend from. If do anything else but limitation of IR you would be leaving yourself wide open. A limitation would not render cert non compliant. An IR <1 meg would.

 

[FreeLec]

When I did put LIM on the cert my boss said to still test and put the result even if it was 0.00 Meg.

The only problem is that you can't put LIM somewhere where there is no genuine reason for limitation.
I'm sure the IEE or NICEIC would not accept LIM because of time constraints on the job.
A genuine reason would be LIM between L and N and that's what's put down. Your not expected to disconnect everything.
Now, I've just realised what I've just typed. If that's the case between L and N then why should it not be the same with L-N and E. There's a contradiction there.

I'm going to have to have a think about that. LIM is allowed for L to N on existing circuits as you're not expected to remove every item of equipment. Why should it not be the same for IR test to E?
Of course. Because there could be a fault to earth and by not testing and removing any item of equipment causing it you won't know that there is an actual fault on the circuit itself. Mind you, the same could still be said of a L to N fault. It seems acceptable to have a possible L to N fault but not a L or N to E fault.

Am I missing something or does this seem contradictory.

Or is it because it's 12:00 at night and I'm about to fall asleep in front of the PC.
Time for bed. I have to get up at 04:30

 

[TJ Anderson]

There should be no remedials, the job should be surveyed and priced accordingly before hand. Filling out a EIC with unacceptable results isnt something that should be done on a job. Any discrepancies should should be sorted before any works are carried out.

That is not in anyway helpful or telling the OP anything he does not know. He is well aware of this, hence his post.

 

[Richard Burns]

Just remember that the result you are putting down is not (in most cases) a non compliance with BS7671 it is just a result that has been obtained inaccurately.
If disconnecting connected loads gives the circuit an IR value that is within the limits then the circuit was compliant.
The problem you have is that you are unable to state whether or not the circuit is compliant at the time of install because of the method of testing.

You state that you feel you should test the entire circuit and this is a good approach even if it is not required as your work is the changing of a fitting and (presumably) you are doing this part in compliance with BS7671.

A minor works certificate states that the installation work does not impair the safety of the installation, if it is done correctly then your work will not impair the safety of the installation.
The installation may already be unsafe, but outside of your control.

The certificate should not be issued with false results but should be issued with the proviso that the measured IR on the existing circuit was outside of the limits of BS7671 and the situation should be investigated, then you have issued a valid certificate but raised the issue of the possible non compliance with the existing installation.

 

[davesparks]

First con I've ever come across where it's agreed with the client to con him..:wink5:

Really? It's going on every day in commercial work.
People in offices taking backhanders to sign off on unnecessary extra works.
In this case it's a school which may very well mean it is ultimately us taxpayers who are financing this little racket.

 

[davesparks]

DAVESPARKS

I have just noticed your stupid and ignorant comment.

If I was not competent I would not know that something was not right.
I already said that I did not feel happy about the way I am being asked to work.
I am being told to work that way.
I am installing about 50 bulkhead emergency lights next to existing failed integrated fittings.
It is in a school where I have to drag tools, materials, rubble bags, vacuum cleaner, etc between 14 different buildings and back to the same ones as different rooms are being used at different times.
I have to get each one done as quickly as possible within the allocated time.
I have not been given time to disconnect any item of equipment not allowing an acceptable IR result.
I've been told to put a failed IR on the MWC with a comment about why the result is likely + further investigation required.

Maybe you should think it bit more and read the post properly before you make nasty comments.

So quit and go get a job elsewhere, if you are indeed a competent electrician then you'll have no trouble getting another job.
'I was told to do it that way' will not stand up as a defence in law, as a competent person you are responsible for what you do.

So get something with wheels on it to move your gear around the different rooms, it's hardly rocket science!

If you have allotted time for a job why do you have to get it done as quickly as possible? The whole point of having an allotted unit of time is that you have that whole unit of time available.

On that subject, how much time have you been allotted to complete each light?

 

[davesparks]

NOT NICE TO SEE COMMENTS LIKE THIS!!! As it says by moderators if your reply cant help the OP then dont reply, that is just rude to a person who obvious is concerned and reaching out for help over something he has concern for!

I agree it isn't nice to see comments like that, but what would you call someone who comes onto the forum and tells us that they are carrying out testing incorrectly? Are they competent or incompetent?

 

[YoungBart]

I wouldn't feel comfortable putting either LIM or a low IR reading down on a test cert of any type. Especially If I can't verify the wiring, I appreciate to remove all emergency lights or other loads is a pain But if I got a low IR I'd be trying to get it to an acceptable result however long it takes. Afterall It could be a potentially dangerous fault. I wouldn't be happy if my name was on the cert if a potential fault was not found.

 

[Risteard]

It is in a school where I have to drag tools, materials, rubble bags, vacuum cleaner, etc between 14 different buildings and back to the same ones as different rooms are being used at different times.

Other than during school holidays, most (although admittedly not all) of the work in schools that I have done has been nightshift to avoid these sorts of problems.

 

[davesparks]

Other than during school holidays, most (although admittedly not all) of the work in schools that I have done has been nightshift to avoid these sorts of problems.

Having done maintainence work for a local school it was always between 7:00 and 8:30 before the kids arrive or weekends for bigger jobs

 

[Risteard]

Having done maintainence work for a local school it was always between 7:00 and 8:30 before the kids arrive or weekends for bigger jobs

I did 3p.m. to 3a.m. for just shy of six months in a few schools.

I can only think of one firm I worked for where we were in schools during school hours.

 

[Andy78]

I once did a job whilst employed for a firm that involved a full new fire alarm system in a large, multi building, secondary school, all in school hours, for months. Talk about nightmare !!
Most of the work was done in bits and bobs amongst rescheduled classes that totally ruined our pre-arranged schedule of access to areas. Most of the time was spent idling around waiting and exchanging "pleasantries" with the gobbier kids.

To make the job even better, the contract had been won as part of a deal that had us doing the school's PAT, at cost, on an estimated 6000 items. We all had to take it in turns...

 

[ipf]

Really? It's going on every day in commercial work.
People in offices taking backhanders to sign off on unnecessary extra works.
In this case it's a school which may very well mean it is ultimately us taxpayers who are financing this little racket.

:wink5:......notice.

Certainly not just in commercial.

Just give the lad a bit of leeway. It's not all black and white and I would expect you to know that.

 

[FreeLec]

Finally got it sorted out with the supervisor.

I called NICEIC and told them about the situation. They said what I thought they were going to say but it confirmed what I already new and I could then have backup for my assertion.

I have had many different versions of what can be done like, "you only need to test the new part of the circuit" etc, but simply stated the whole circuit is tested as to fitness before work and the MWC confirms fitness of the circuit. No loopholes etc.

The supervisor came to site today and, after discussing this with another who spark who is working in the same place but doing something else, we talked to him.
He said that there has been a misunderstanding as a result of both the boss putting pressure on everyone to get things done within his schedule and pure panic from the other sparks and mates.
This resulted in ignoring things that should not have been ignored and, I got caught up in it.

As and example, a job we had previously done about 10 weeks ago. I won't bore you with the details but 4 weeks ago 3 of the 100 fittings began to fail. When the maintenance supervisor dropped the fitting and looked inside the coffin boxes the wiring which had been heat damaged was not cut back. We're talking about heat damaged insulation so bad that when you bend it it cracks and fall off. They used the old earth sleeving that had browned. We had a hank of sleeving so I don't understand such laziness.
That was in the coffin box behind the fitting. New here's the most unbelievable bit. We were using butyl flex from the coffin box to the fitting. They were putting the switch line link to the perm feed in with the old core that had cracked and flaked off.

He showed me a picture. I couldn't believe it. We know who the culprits are because none of the other four of us that were on that job would ever do such a thing. Problem is we don't know which one.
One is an apprentice. The other went to collage to get his papers but does not have the understanding and never will. When working with him once on fixing lighting that wasn't working I hit the ceiling to steady myself at the top of the steps and the light came on. He said he wanted to move straight onto the next one as that was now working. Bloody hell. I knew, even when I was a kid, that there must be a loose connection that couldn't be left like that. We ended up arguing over it.

The apprentice is too relaxed in his approach. Both of them don't seem to want to learn new things. I find that really frustrating working with them as I am always looking to improve my knowledge and skills and when I want to check something out when I don't really need to but want to to get a better understanding of it's construction or operation they moan.

For the last few weeks someone has been going round to all the ones in the suspect positions and sorting them out.
I don't know what the supervisor and boss are going to do about this as they have not told us. I suppose it's their business but it's not made them look too good with the client.
Even I feel embarrassed and I had nothing to do with the bad workmanship.

Anyway, to get back to the subject at hand, even the other 2 sparks who would never do that were still panicking about keeping to schedule and that we can't just stop work to properly sort things out. I was for feeding any free cable through the wall from the other side, get heat shrink etc. "No, we don't have time to do a perfect job,". I said that due to the state of the wiring we should stop and IR test the circuits. You would have thought I had just suggested that we all work in the nude. So although they wouldn't have done what the other two had done they still could have done better.
Unfortunately, under pressure I went along with it.

Now at this school under discussion I carried on the same panicky, "I've got to get this done" attitude.


My supervisor said that from now on do what I think is right and don't get pressured. If I thing something is wrong, no matter what anybody else says or does, stop work and report it.

I should have known better but after two years of working with panicking sparks I ended up the same.

Still, every experience is good. Even the bad ones. At least I won't let this happen again.

He did pay me a compliment, though, that set me up for the day. When I said that "I know I'm not the fastest but working with the others who are faster....
He interrupted me and said "You're not slow. Your methodical". A boost to the ego I think. At least he recognized that I don't like to just lash it in. I like to do things properly. Up to now I thought he considered me as too slow.
He said that how many of the others know the things you know. He mentioned my understanding of lighting systems from the differences in glow starters to semi-resonant, DALI DSI 1to10 Lutron Thorlux Thorn controls etc. Whenever there is an existing system they call me as they can't work out what's happening. I understand motor controls, heating controls, etc which I find that only a minority of sparks seem to understand. I must admit, my lack of speed has left me feeling a bit inadequate, so find it hard to contradict when I think something is wrong. In that post some have used that as a "who do you think you are telling us when you work slower then us".
No more. From now on it's "I may work slower that you but I still know when you're doing something wrong"

Anyway, enough or my rant. I wasn't originally going to go on like this.

Today was a good day. I only had to stop a few times when the schoolkids came down the corridor like a herd of bulls. This lasted for 20 mins. Not long after it happened again.
Still, better than starting something and then someone walks in and says I have to stop.

No arrangement at all. It's all left up to me on the fly.
I come in at 06:00 and get as much done as I can when it's quite. Then the nightmare.
I can't understand why this can't be done at night. I would have been done by now. What's taken 3 weeks could have taken 1 week.
Still, it will be finished tomorrow.

The pressure is still there from the boss. We have WhatsApp on the mobile and every single thing that causes any form of a delay from the basic no problems encountered (real world?) install now has to be put on there. Even when we start lunch and finish lunch.

Before anyone says why don't I get another job; this one is convenient to me at the moment despite the hassles for various reasons that I don't want to go in to. I don't intend staying indefinitely though for other reasons that I don't want to go into.

As far as the other thing goes that Lucian was mentioning, I will put this up on a new post drawing attention to it by putting his name in the heading with something like IR testing with electronics. That way anyone interested in that part of this post will see it.

Bloody hell. Look how much I've typed. I got a bit carried away.
I think this post is all probably all talked out now. Nothing much more to be said that hasn't been said, so that's it.
Thanks for your replies.

 

[Midwest]

'Its good to talk'.

 

[FreeLec]

..... :28: