Erroneous connections

[Sintra]

Do any of you guys test for erroneous connections when you are doing your IR tests?

 

[ezzzekiel]

long time since i checked for a erroneous zone, still never found one according to the wife

 

[pushrod]

long time since i checked for a erroneous zone, still never found one according to the wife

was thinking the same myself lol

 

[terminator]

Can you expand on that Sintra - In what context do you mean?

 

[Sintra]

An erroneous connection is a physical connection between 2 circuits.

Have you ever been in a situation were you have opened a breaker and the load side is still live?
An example of this could be 2 radial socket circuits with the phase linked between the 2 circuits.
2 phase conductors fused together inside containment due to heat or installation methods i'm sure you get my drift by now.

The reason i posted this is because i found such a situation yesterday and luckily the guy that i learnt from told me always to do this test while carrying out the IR tests.

The test procedure is as follows.

IR tester on 500V

Main switch open all MCB's closed except for the first one that you are going to test which should be open.
One probe on to MCB supply bus bar and 2nd probe on to load side of breaker that was left open.
Apply 500V.
Repeat the process by opening the next MCB and apply test voltage to load side.
Repeat for all breakers.

 

[telectrix]

from that post, sintra, i assume a zero or low reading will tell you that you have got a cross connection, if i am reading it correctly.

 

[Sintra]

Yes Tel zero or low means cross connection. I would be looking for readings greater than 1 megohm.

 

[pushrod]

Hi Sintra, wouldn't safe isolation with an approved voltage tester be another way of doing the same thing?

Or do i go the to the back of the class with Ezzze

 

[telectrix]

Hi Sintra, wouldn't safe isolation with an approved voltage tester be another way of doing the same thing?

Or do i go the to the back of the class with Ezzze

up to a point. if there was a short, you'd read 230v, but if insulationn breakdown, your tester might not show a reading.

 

[pushrod]

up to a point. if there was a short, you'd read 230v, but if insulationn breakdown, your tester might not show a reading.

Got you now, cheers.

 

[MarkieSparkie]

I do ever since being confronted by a "downstairs ring" interconnected to an "upstairs ring".
Turned out that some bright "spark" working for a kitchen unit company (Moben) had decided not to run a new separate ring for the kitchen. Instead he connected the new kitchen sockets ring extention into one leg of downstairs ring and the other end into a leg of the the upstairs ring, bridging both rings.

 

[Sintra]

Hi Sintra, wouldn't safe isolation with an approved voltage tester be another way of doing the same thing?

Or do i go the to the back of the class with Ezzze

Safe isolation would be fine if you are a competent person going to work on a circuit. But Mr DIY goes to change an accessory he knocks off breaker for the circuit and proceeds to get a shock. If you or I have done work and issued a cert for say a cu change I think we could end up in the big house.


Sent from my iPhone using Tapatalk.

 

[nickblake]

I always do it when i carry out an inspection especially when working on old houses or houses where Mr DIY come in and says i put that socket in whilst grinning like a cheshire cat , found one last week whilest doing a CDU up grade carrying out some initial tests as i always do ,ring and immersion heater supplies crossed so like been said its ok if professionals do are working on it they can spot it

its like anything realy test before you isolate and after you isolate ,test test and test again ,have seen so many people say its still live after theyve touched a live part