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........