Insulation Resistance Testing - necessary ?

[Bazabacon]

Recently my boss and I were changing a fuse board(old to new). It was a shared house and some of the tenants were out at work and their doors locked. Not knowing what they had plugged in, in their rooms we skipped the Insulation Resistance test. Everything else was tested fine. My question to him was obviously - is that cocha ? He said strictly speaking that the RCD would trip out if there was any issue with the insulation, so it was ok to bypass it. Thoughts ?

 

[Kate]

No. At very minimum I would test at 250v.
How can you have completed the test cert if you didn't have access to the circuits??? If you can't access rooms you can't have done the other tests properly. So your 'everything else was tested fine' comment it bullsh1t

 

[Bazabacon]

No. At very minimum I would test at 250v.
How can you have completed the test cert if you didn't have access to the circuits??? If you can't access rooms you can't have done the other tests properly. So your 'everything else was tested fine' comment it bullsh1t

yeah - obviously we couldn't get in to the rooms to test everything, but the rooms that we had access too, we tested. I have only been doing this a year, so my question is borne out of coming out of college where EVERYTHING is done by the book and to the letter of the law to the REALWORLD where obviously on occasion you cannot do everything by the book. Don't get me wrong I don't want to be taking shortcuts, but as I have little experience I guess, I'm basically asking , does my boss sound like a bit of a cowboy ? and would a 250 v test take any plugged in appliances out ?

 

[oldtimer]

Having to agree with Kate on this as I am seeing a lot of this where the mentality is if the RCD does not trip then its fine. Well not really as for the insulation test he could have done a combined LN-E 250v IR test.

Plus you can tell that when an OP comes on with the famous Help ! RCD is tripping type of post ? so again before a CU is changed do a Ze,PFC,PSSC, and a global LN-E 250 IR test and then you will have a chance.

 

[crow11]

as kate said how could you have provided a full cert if you haven't tested all the circuits, you don't know what is going on in them other rooms, you need to get into them other rooms to complete the testing, with the attitude of your boss why doesn't he just skip all testing and just switch on and hope for the best hopefully the rcd will trip if anything wrong, if it was me i wouldn't of been energizing them circuits until i have tested, think of it as your house would you be happy for someone to take shortcuts on something which could be dangerous, did your boss actually provide a eic for this job

 

[Bazabacon]

Having to agree with Kate on this as I am seeing a lot of this where the mentality is if the RCD does not trip then its fine. Well not really as for the insulation test he could have done a combined LN-E 250v IR test.

Plus you can tell that when an OP comes on with the famous Help ! RCD is tripping type of post ? so again before a CU is changed do a Ze,PFC,PSSC, and a global LN-E 250 IR test and then you will have a chance.

As I say, I have no other experience to compare my boss against. Sometimes I have wondered if he's cutting corners or not. I guess by your replies he is. I seen him drill a hole in the wall the other week and the cables were still live. I was then tasked with chasing out the wall for a backbox on the other side of the hole, where I discovered he was literally millimteres away from live wires. I told him and he just grumbled something. Made me have a bit of a think. I do want to learn, but I want to learn the RIGHT way

 

[Kate]

From your original post I knew you were a trainee. Im just a bit mad someone is showing you wrong. Your doing the right thing asking, I also know its impossible for you to realistically point all his flaws out to him as you would most likely get the sack. Keep asking us questions and when you do your own work do it right!

I do 250v IR on lighting as im worried about blowing every lamp!! And with modern tech of downlighters theres just too many lamps to remove.

 

[Bazabacon]

From your original post I knew you were a trainee. Im just a bit mad someone is showing you wrong. Your doing the right thing asking, I also know its impossible for you to realistically point all his flaws out to him as you would most likely get the sack. Keep asking us questions and when you do your own work do it right!

I do 250v IR on lighting as im worried about blowing every lamp!! And with modern tech of downlighters theres just too many lamps to remove.

Cheers for that. I am in a bit of a jam as you say. It's experience, but as I say I want the right kind of experience. The guy I work for has been doing it 20 yrs and to be fair I have seen him do good jobs as well as ones where I think, "this feels a bit shoddy ". Is a 250 v IR test fullproof as in it won't take anything out - ie phones, computers. I guess nominal voltage is 240 + or - 6 volts so I'm guessing it's sound ?

 

[Kate]

I wouldnt like to give a definitive on that. But in all my years nothing has broke when ive done it!

 

[telectrix]

if you short L to N and the IR test to E, you'll not harm any equipment ( hopefully).

 

[shanky887614]

nonminal voltage isnt usually 240 ive seen as low as 220 and high of 255 before.

new subs are supposed to be 230 but i doubt they will be

 

[Guest55]

But in all my years nothing has broke when ive done it!

you still need more practice then , the very best sparks will have trashed 000's of pounds worth of gear by the time they've reached the peak of their careers.

:-D

 

[Octopus]

Love to see the cert he filled out!

 

[44ALLAN]

you still need more practice then , the very best sparks will have trashed 000's of pounds worth of gear by the time they've reached the peak of their careers.

:-D

And the clever ones blame somebody else :smug2::wink_smile:

 

[Kate]

Done enough while pat testing!! Im sure I will though! Im only 26 got 40 odd years yet lol