Line & Neutral Testing

[EddieB]

When testing an existing circuit lighting circuit I found that there were a great many 12v lights in the bedrooms and bathroom and was unable to access some of the transformers therefore I was unable to test between line and neutral with the switches shut, would this be acceptable on the schedule of tests and should it be noted on the limitations part of the certificate.

 

[Guest123]

Hey Eddie

Is it a PIR your doing??

 

[EddieB]

No Len it's a replacement consumer unit

 

[Spudnik]

Test between line& neutral together and earth @ 250V.

 

[EddieB]

Jasons 6939
I have tested Line to earth and Neutral to earth already they read fine, its the resistance between L&N I need, I'm not missing anything here am I?? what does the L&N together to earth as you suggest actually do.

 

[slocm3105]

Just write LIM in the box mate

 

[EddieB]

Slocm old mate as much as I admire the use of TLA's whats a LIM??

 

[Guest123]

Hey.

He maens Limitation, as in limitations on inspection and testing.

I dont know if I'd be happy with that though.

As Mr Mod said testing at 250V is safer as that is the voltage at which the transformers operate so they would not be damaged by the test.

Cheers

 

[Des 56]

Doing an insulation resistance test on a 230 volt system at 230 volt and using that test to confirm satisfactory insulation resistance would not be recomended
By all means use a 230 volt test to check if anything is left in circuit,neons lamps transformers etc ,but as you know the test at 500 volt is used to see if the insulation properties are breaking down
Some people test between neutral-earth with the switches open when in your position,thereby making sure the switch wire to the light is included in the test I dont do this because if there was a fault on that leg then the transformer can be damaged by having the 500 volt applied to it in these circumstances
I would recomend do as suggested and link live and neutral together and test to earth This way the transformer is in effect shorted out and cant be damaged by a fault causing a closed circuit
This test is acceptable where lamps cant be removed or in your instance with transformers