Testing r1+r2

[beanzntoast]

its me,
Hi all,new to testing so go easy on me if it's a silly question,On a periodic when testing r1+r2 & zs on a lighting circuit with ELV downlighters fitted how is it done.If the transformers are not accessable for bypass or disconnection is the r1+r2 test just done up to lightswitch or would it just be agreed as a limitation not to do the above tests with the customer & noted on the test results & just do the IR test with L&N connected together & test between earth.As i said go easy as experience will come eventually

 

[sparks1234]

Are we getting confued with R1/R2 and insulation resistance here?

 

[beanzntoast]

Are we getting confued with R1/R2 and insulation resistance here?

No mate,maybe i didn't explain it clearly.what i meant is i could do the IR test in the procedure i stated because the transformer cannot be disconnected but for the r1+r2 test be carried out what would be the procedure.Does that make sense to you

 

[securityvillage]

You should have an idea of when the work was carried out. The extent of the installation and limitations should have been discussed prior with the client. You test what you can get at and note this on the report.

 

[Des 56]

I wouldn't be too concerned with r1+r2 value
If they were class 1 fittings then yes it would be important to ascertain the r1+r2
The cpc is not going to carry a fault current unless its a cable fault
I would be much more concerned that the transformers were inaccessable in the first instance
I would prefer to know that there is sufficient ventilation around them and they are not covered in the wooly stuff
Anything that is not tested should be agreed and noted as a limitation
If testing r1+r2 can only go as far as the switch then have that agreed and noted
In the end you are not there to rip the install to bits for the information
The insulation resistance test sounds reasonable to me
You should have access to the transformers for the test between the supply and the selv to test for seperation

 

[chocolate]

If its a PIR, then you note it that the transformers were inaccessible. So you carry out the r1+r2 at the most convenient points on that circuit. Make a note that you are unable to verify connections at these transformers too. Why can't you get to the transformers ?
You are correct in doing the IR test by linking together the L and N conductors, and testing to E. Again, the L-N IR test must be noted as a limitation due to connection of equipment which could not be disconnected.

 

[sparks1234]

When you say they are innacessible, do you mean they are behind the fittings themselves

 

[beanzntoast]

If its a PIR, then you note it that the transformers were inaccessible. So you carry out the r1+r2 at the most convenient points on that circuit. Make a note that you are unable to verify connections at these transformers too. Why can't you get to the transformers ?
You are correct in doing the IR test by linking together the L and N conductors, and testing to E. Again, the L-N IR test must be noted as a limitation due to connection of equipment which could not be disconnected.

Thanks this answers all my Questions so thanks for all the replies.The transformers are inaccessable because they are not behind the fittings they are somewhere under the floorboards & customer does not want carpets/floorboards ripping up & neither do i