Period Inspection Report IR test on lighting at 250V

[thomo27]

Evening all

When doing a Period Inspection Report and you come across a lighting circuit with lots of lighting points and lamps and when it is seemed unpractical to remove each lamp do you test at 250V and note this in limitations ??

 

[Spark123]

I connect L&N together and test to earth @ 500v.

It is also possible to test as normal with the switches open, bit of a limited test if the lamps are not filament and doesn't work if there are any emergency lights or other apparatus connected permanently L-N.

 

[RF Lighting]

You shouldn't be testing any LV circuits at 250V

 

[Adam_151]

Yeah as spark 123 says, test between L+N joined and earth, note it down as a limitation that no L-N IR carried out

Sometimes just to be on safe side I do it at 250v first and then go to 500v after as long as it doesn't fail... note the 500v result

There isn't much that will keel over at 500v LN to earth though... things to watch out for are RCBOs and RCD socket outlets

 

[1john]

what makes it safer to do it at 250V first? more to the point how is it more dangerous to do it at 500V ?

230v circuits must be tested at 500v, this is basic stuff.

 

[Spark123]

Sometimes people test at 250v first as it is less likely to blow the crap out of any semiconductor devices which may be connected.

 

[1john]

but as the op described, the only way you would test that installation would be to remove everything or join phase and neutral and test to cpc. basic knowledge.

 

[electronicsuk]

but as the op described, the only way you would test that installation would be to remove everything or join phase and neutral and test to cpc. basic knowledge.

And what if you missed/forgot to disconnect something? the 250v test prior to 500v will show it up, hopefully without damaging anything - you can then investigate further before running the 500v test.

 

[londonboy]

I put my tester on low ohms and test between L and N before doing any 500v IR's. This shows up any connected loads.

 

[GaryMo]

You should always omit L-N testing on unknown circuits unless you can visually see the entire circuit and know for sure there aren't any sensitive device still in circuit.

It's not worth the hassle of having to replace an item when it's acceptable to omit L-N IR testing.

Obviously if it's an initial verification then that's another matter as you shouldn't have connected any sensitive equipment at this point.