IR test whats the point?

[nick611]

what is the point of an IR test? yes i know its to show low risistance on cable insullation [its in the name] and that can lead to short circuit and fire risk, but with the protection we use now wont this show its self eventually. what do you tell a customer in a nursing home ? that his IR is a bit low and some time in the future he may get a problem. HE says when,and you say,i dont know,he says,what,and you say,i dont know. AM i the only one who thinks while IR testing with all the ******* hassle that goes with it. WHATS THE POINT

 

[malcolmsanford]

Is this a wind up?

 

[nick611]

Is this a wind up?

no its not, i am asking for your views,this is a forum. how many problems have you identified in advance through IR testing? and how did you overcome them.would you for instance replace a submain because of a low IR before it had caused any real problem.and how would you justify this to the person you wanted to pay for it?

 

[gamblor6]

i sometimes find low ir on lighting circuits n to e that some sparks had just put on a 60898, we.re putting 61009s on and without the ir test i would have no way of knowing if the rcbo would hold.

 

[malcolmsanford]

Sorry Nick but i'm suprised.

Ok IR a circuit on a CU change as many faults that hold in on a fuse/mcb will trip on RCD/RCBO

On a PIR it will give you an indication on an older installation that there can be a problems developing. So you will alter the time frame of the next PIR to say 5 tears or even less.

On an initial verication it will tell you if your circuit as been damaged. You may have first fixed the before someone put a nail through your cable, it will stop you energising the circuit.

Again On fault finding it will help.

 

[nick611]

yes i see but on a domestic 17 edition board the rcd will find any l-e and n-e faults and the mcb any l-n faults so on a piriodic why IR test given the time and hassle [disconecting this and that] it takes. just a thought

 

[telectrix]

why not just power it up and see if it goes bang.

 

[tony mc]

You are trying to identify any future problems with the wireing in the instalation and if the insulation is starting to deteriorate the customer needs to know. Like Malcolm has said the inspection time can be reduced to see if the problem is getting worse.

Low IR readings don't just indicate that the cable insulation is failing as it could be other issues like dampness getting into joint boxes under the floor etc.

If the IR reading on the whole instalation was low then I would be testing each cct to find out if one particular cct was bringing the readings down and try and locate the cause.

I am sure if you did locate a joint box full of condensation because it was lying on the ground and the readings were now more healthy the customer would be alot happier.

In a Nurseing home I am sure that the insurance company will have there say re the report and they won't be happy to rely on 17th edition boards they will be looking at your report making sure that the home is safe and what needs to be done to keep it that way IMO.

 

[ezzzekiel]

not many other ways to locate a fault either

 

[telectrix]

not many other ways to locate a fault either

i find an uninsulated screwdriver is best for finding insulation faults. or a couple of horses........

 

[oldtimer]

Look at it this way years ago people said you should rewire every 30 years yes some would say but we have new type pvc covered copper cables and depending on its condition it could last years longer so just like a car on a mot test the garage tests the emissions and as they gradually get worse you get a warning to either repair or replace the engine. A PIR as far as I am concerned is a MOT for a buildings electrics and the IR test is telling you keep an eye on this you may have to repair/replace in the future and as for "why not let the RCD board tell you when there is a aproblem" the whole reason of IR testing is to prevent this from happening if you really want to question testing then point it in the direction of PAT testing.

Mind you our new primeminister says he is going to make it easier for small business by doing away with "crazy regulations" so heres hoping he might even get I&T sorted out ie 2 hours for a PIR but somehow me does not think so.

 

[mayfair]

You been reading the new amendments to the 17th, bet thats there advice

why not just power it up and see if it goes bang.

 

[mayfair]

sorry m8 but your wrong thats the test for rcds

i find an uninsulated screwdriver is best for finding insulation faults. or a couple of horses........

 

[telectrix]

sorry m8 but your wrong thats the test for rcds

what, the driver or the horses?

 

[mayfair]

Horses you see how many ms it takes for them to shout naaaaaaaaaaa thats for 1x ie 1 horse its different for half a horse and 5x ie 5 horses

what, the driver or the horses?