Neons on IR test .....

[swparksey]

Only way to learn is ask questions bud

 

[Des 56]

Unlikely deterioration of insulation ( Pvc )
Extensive and expanding use of functional earths,electronic controls,neon lights,low voltage equipment
RCDs on most (domestic) installations
Material properties that are far in advance of what was available in the past

A sample list of why the insulation resistance test is fast becoming an un necessary or at the least, a less important test than we would be ready to accept

It is also becoming a possible "danger to equipment" test
In the near future, possibly the rule makers may have much less emphasis on this hyped up test than there is at at present

It doesn't have the importance it once did,especially initial verification
The cable insulation will either be sound or a connection or damaged cable will not be sound
Things like damp ingress into equipment, is more often than not picked up by Rcds
Low readings of insulation values are mostly confined to the likes of older installation materials


Insulation resistance ?
"remember when we used to do those tests"

 

[Jimmy Boy]

Des what an interesting observation.

How many IR's fail ?

Lets say for a board change

 

[Des 56]

I'm glad you described my post as an observation,because that is all it was meant to be
I will be clear and say that whilst the rule makers say it is important, then I will follow sheepishly

I made the post because the arguments for and against the method of doing this test,didnt mention the reasons for the test at any time

I do believe that the test is of much less importance than earth continuity or Ze or Pfc
The extreems that are suggested to carry out this test goes well beyhong what I personally would carry out for an initial verification

I believe changing a consumer unit is a different kettle of fish
By the very nature of the job,it is for older or outdated installations where the insulation resistance test becomes more important because of older materials deterioration and unknown damp and earth fault possible problems

After all its just an opinion,but also a chance to broaden the subject of the thread

 

[swparksey]

I think you should look upon an insulation resistance test on initial verification as a quality check, whilst it is unlikely a brand new length of PVC cable will have a problem, it is not beyond the realms of possibility.

Then on older installations it is a useful tool in determining the condition of the installation.

 

[Jimmy Boy]

Des you have opened this in to an interesting thread !

As proved tonight by discussion and not confrontation we can all learn something !

 

[jules27]

good discussion was helpfull cheers