IR Testing on domestic installations.

[electek]

<div class="bbWrapper">Hi All ,<br /> When testing insulation resistance on a domestic lighting circuit do you just join live/neutral and test down to earth otherwise if your testing live to neutral presumably you have to close all switches and remove all the lamps in the circuit. <br /> <br /> Thanks Chris</div>

 

[electek]

<div class="bbWrapper">Sythai , Yep , let me know mate - good luck hope all goes well<img src="https://cdn.jsdelivr.net/gh/twitter/[email protected]/assets/72x72/1f642.png" class="smilie smilie--emoji" loading="lazy" width="72" height="72" alt=":)" title="Smile :)" data-smilie="1"data-shortname=":)" /></div>

 

[nickblake]

<div class="bbWrapper">elect yes it is , im a funny bugger like to do them seperate<img src="https://cdn.jsdelivr.net/gh/twitter/[email protected]/assets/72x72/1f600.png" class="smilie smilie--emoji" loading="lazy" width="72" height="72" alt=":D" title="Big Grin :D" data-smilie="8"data-shortname=":D" /></div>

 

[Des 56]

<div class="bbWrapper">An insulation resistance test is done over the whole of the installation<br /> It needs to be done on individual circuits only when a problem may exist</div>

 

[electek]

<div class="bbWrapper">Des 56 , yep , i&#039;m aware of that but i was wondering how you would do IR test on a lighting circuit if asked to do so on the actual part &#039;p&#039; assesment ? <img src="https://cdn.jsdelivr.net/gh/twitter/[email protected]/assets/72x72/1f642.png" class="smilie smilie--emoji" loading="lazy" width="72" height="72" alt=":)" title="Smile :)" data-smilie="1"data-shortname=":)" /><br /> <br /> Regards<br /> Chris</div>

 

[Risteard]

<div class="bbWrapper"><blockquote data-attributes="" data-quote="Des 56" data-source="post: 122180" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> <a href="/goto/post?id=122180" class="bbCodeBlock-sourceJump" rel="nofollow" data-xf-click="attribution" data-content-selector="#post-122180">Des 56 said:</a> </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> An insulation resistance test is done over the whole of the installation<br /> It needs to be done on individual circuits only when a problem may exist </div> <div class="bbCodeBlock-expandLink js-expandLink"><a role="button" tabindex="0">Click to expand...</a></div> </div> </blockquote> <br /> And if it is done on circuits individually then calculations would need to be done to ensure that the installation is satisfactory, i.e. 1/Rt = 1/R1 + 1/R2 etc.<br /> <br /> The values in BS7671 relate to the installation/dis. board - not to individual circuits!</div>

 

[WayneL]

<div class="bbWrapper"><blockquote data-attributes="" data-quote="Risteard" data-source="post: 122370" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> <a href="/goto/post?id=122370" class="bbCodeBlock-sourceJump" rel="nofollow" data-xf-click="attribution" data-content-selector="#post-122370">Risteard said:</a> </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> And if it is done on circuits individually then <b>calculations would need to be done to ensure that the installation is satisfactory, i.e. 1/Rt = 1/R1 + 1/R2</b> etc.<br /> <br /> The values in BS7671 relate to the installation/dis. board - not to individual circuits! </div> <div class="bbCodeBlock-expandLink js-expandLink"><a role="button" tabindex="0">Click to expand...</a></div> </div> </blockquote> <br /> <br /> Are you saying that if you IR tested six circuits individually, and they each gave a reading of 5 M ohms, the installation wouldn&#039;t comply, and you would fail it.<img src="https://cdn.jsdelivr.net/gh/twitter/[email protected]/assets/72x72/1f600.png" class="smilie smilie--emoji" loading="lazy" width="72" height="72" alt=":D" title="Big Grin :D" data-smilie="8"data-shortname=":D" /></div>

 

[Risteard]

<div class="bbWrapper"><blockquote data-attributes="" data-quote="WayneL" data-source="post: 122600" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> <a href="/goto/post?id=122600" class="bbCodeBlock-sourceJump" rel="nofollow" data-xf-click="attribution" data-content-selector="#post-122600">WayneL said:</a> </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> Are you saying that if you IR tested six circuits individually, and they each gave a reading of 5 M ohms, the installation wouldn&#039;t comply, and you would fail it.<img src="https://cdn.jsdelivr.net/gh/twitter/[email protected]/assets/72x72/1f600.png" class="smilie smilie--emoji" loading="lazy" width="72" height="72" alt=":D" title="Big Grin :D" data-smilie="8"data-shortname=":D" /> </div> <div class="bbCodeBlock-expandLink js-expandLink"><a role="button" tabindex="0">Click to expand...</a></div> </div> </blockquote> <br /> If below 2 Megohms then you would need further investigation, i.e. checking individual circuits. You already have the values for the individual circuits.<br /> <br /> The point I was making was that the insulation resistance value is not just fo the circuit (read the Regulation carefully).</div>

 

[WayneL]

<div class="bbWrapper"><blockquote data-attributes="" data-quote="Risteard" data-source="post: 122602" class="bbCodeBlock bbCodeBlock--expandable bbCodeBlock--quote js-expandWatch"> <div class="bbCodeBlock-title"> <a href="/goto/post?id=122602" class="bbCodeBlock-sourceJump" rel="nofollow" data-xf-click="attribution" data-content-selector="#post-122602">Risteard said:</a> </div> <div class="bbCodeBlock-content"> <div class="bbCodeBlock-expandContent js-expandContent "> If below 2 Megohms then you would need further investigation, i.e. checking individual circuits. You already have the values for the individual circuits.<br /> <br /> The point I was making was that the insulation resistance value is not just fo the circuit (read the Regulation carefully). </div> <div class="bbCodeBlock-expandLink js-expandLink"><a role="button" tabindex="0">Click to expand...</a></div> </div> </blockquote> <br /> I know, I&#039;m just causing trouble - that&#039;s why the big cheesy grin<img src="https://cdn.jsdelivr.net/gh/twitter/[email protected]/assets/72x72/1f600.png" class="smilie smilie--emoji" loading="lazy" width="72" height="72" alt=":D" title="Big Grin :D" data-smilie="8"data-shortname=":D" /><br /> <br /> It&#039;s an interesting scenario, though, &#039;cause it gives an overall resistance of 0.83 Mohms for the installation, yet each individual circuit complies.</div>