Discuss Bit confused here, IR testing. in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

Thommo

Trainee
Reaction score
60
Hi all, this is probably a daft question to most of you.
At training centre I have started dead testing. When I get to the 3 point IR test on a single circuit should I switch off the breaker for that circuit .Hopefully I am correct in removing any lamps on a lighting circuit and turned switches on with all points closed. On a radial or final ring I have closed all points turned sockets on.
I think the procedure may be different when doing a global test, not sure.
Just a bit confused about the circuit breaker as I know it is switched on for continuity of cpc test.
Thanks in advance for any input
 
Hi all, this is probably a daft question to most of you.
At training centre I have started dead testing. When I get to the 3 point IR test on a single circuit should I switch off the breaker for that circuit .Hopefully I am correct in removing any lamps on a lighting circuit and turned switches on with all points closed. On a radial or final ring I have closed all points turned sockets on.
I think the procedure may be different when doing a global test, not sure.
Just a bit confused about the circuit breaker as I know it is switched on for continuity of cpc test.
Thanks in advance for any input
dead testing is what it says. all dead tests (continuity,polarity, and IR) are carried oit with the circuit/s isolated from supply. on new installations, these tests are done even before the circuits are connected or the CU powered up. don't confuse continuity with loop impedance. the latter is a "live" test.
 
dead testing is what it says. all dead tests (continuity,polarity, and IR) are carried oit with the circuit/s isolated from supply. on new installations, these tests are done even before the circuits are connected or the CU powered up. don't confuse continuity with loop impedance. the latter is a "live" test.
Thanks telectrix,
Here’s why I am a bit confused.
Here’s a page from my notes I have been given. I have underlined the reason I am confused.
 

Attachments

  • Bit confused here, IR testing. 9A29A114-D94D-4D7C-A0AF-D78C29643D23 - EletriciansForums.net
    9A29A114-D94D-4D7C-A0AF-D78C29643D23.jpeg
    177.9 KB · Views: 36
You can test circuits for IR individually, or globally. Globally with the breakers on, in order to link them together......more than one circuit, one test, as in many EICR's. Whichever, supply to the breakers must be isolated. It's a dead test.
 
You can test circuits for IR individually, or globally. Globally with the breakers on, linking them together......all one test, as in many EICR's. Whichever, supply to the breakers must be isolated. It's a dead test.
So the answer contradicts my notes. And confirms the way I have been doing it this week, with circuit breaker in the off position
 
No, either way. With IR you're checking for clearance. If everything is 'clear' from each other with a global test, it's OK. If not, you have to split the circuits and test individually to find which is faulty.
With continuity, you can link the breakers, switched on, to earth. Then test at the end of circuit for continuity. If RFC's are involved, each circuit has to be done individually.
Whichever ways, the power is OFF.
 
No, either way. With IR you're checking for clearance. If everything is 'clear' from each other with a global test, it's OK. If not, you have to split the circuits and test individually to find which is faulty.
With continuity, you can link the breakers, switched on, to earth. Then test at the end of circuit for continuity. If RFC's are involved, each circuit has to be done individually.
Whichever ways, the power is OFF.
Thanks ipf clarity . So I haven’t been doing it wrong then.
 
Thanks telectrix,
Here’s why I am a bit confused.
Here’s a page from my notes I have been given. I have underlined the reason I am confused.
You might want to challenge your tutor on that as it potentially dangerous to carry out IR testing on live circuits.
 
Hi all, this is probably a daft question to most of you.
At training centre I have started dead testing. When I get to the 3 point IR test on a single circuit should I switch off the breaker for that circuit .Hopefully I am correct in removing any lamps on a lighting circuit and turned switches on with all points closed. On a radial or final ring I have closed all points turned sockets on.
I think the procedure may be different when doing a global test, not sure.
Just a bit confused about the circuit breaker as I know it is switched on for continuity of cpc test.
Thanks in advance for any input
I think the fact that you have stated you are testing a single circuit changes things somewhat from your notes. If you are carrying out a global test (as per the notes) then all conductors will be connected and protective devices on, with the DB main switch OFF! Your test will clearly be carried out on the dead part of the DB.
But you have stated you are carrying out a test on a single circuit, which is not what your notes are describing. This should be carried out with the line and neutral conductors of the circuit disconnected from the DB but with the cpc still connected to the earthing system.
 
I have thought about it mate, probably too much. Just got a bit confused when I read that note.
Global. By switching on CB's you're linking all the outgoing lives. All neutrals and earths are already linked. Just test once between all. Test between any L-N-E. If all clear....done, all at once.
 
You might want to challenge your tutor on that as it potentially dangerous to carry out IR testing on live circuits.
Sorry I may not have explained myself clearly. I am not testing on live circuits.
[automerge]1593194567[/automerge]
I think the fact that you have stated you are testing a single circuit changes things somewhat from your notes. If you are carrying out a global test (as per the notes) then all conductors will be connected and protective devices on, with the DB main switch OFF! Your test will clearly be carried out on the dead part of the DB.
But you have stated you are carrying out a test on a single circuit, which is not what your notes are describing. This should be carried out with the line and neutral conductors of the circuit disconnected from the DB but with the cpc still connected to the earthing system.
Thank you Radiohead, that now makes sense . Obviously you have read my notes more thoroughly than me.
 
Last edited:
Just a bit confused about the circuit breaker as I know it is switched on for continuity of cpc test.

It isn't always, it depends entirely on how you are doing the test as there are multiple ways to do it.
Assuming you are working on an isolated board then if you are testing continuity of the cpc by the R2 method the circuit breaker has nothing to do with it, also if you are doing R1+R2 with a link at the far end of the circuit the circuit breaker has nothing to do with it.

Obviously if you are testing just one circuit in a live board then you will have the circuit breaker in the open position.

The point is that there is not one fixed way that the test must always be carried out, you need to understand the process, what you are actually measuring and what affects the reading.
 
It's one of those how things are taken when instructions aren't (no offense here Thommo) idiot-proof, that is to say a few more words paint a better picture; 'switched off' could mean in any number of places; main isolator (tails), main switch (board), RCD (split load) or MCB. 'Switched off at main switch (to isolate board) with MCB turned ON (to allow for test to run through entirety of circuit); that paints a much better and clearer picture

I can be a right ----hat (yes @telectrix I'm sure you'll quote this as many times as possible, on and out of context?) when it comes to clear instruction, if I complete task and it's not to the unspoken standard whoever set the task then i make sure they know that, am sure I'm not the only one ?
 
Hi all, this is probably a daft question to most of you.
At training centre I have started dead testing. When I get to the 3 point IR test on a single circuit should I switch off the breaker for that circuit .Hopefully I am correct in removing any lamps on a lighting circuit and turned switches on with all points closed. On a radial or final ring I have closed all points turned sockets on.
I think the procedure may be different when doing a global test, not sure.
Just a bit confused about the circuit breaker as I know it is switched on for continuity of cpc test.
Thanks in advance for any input
Circuit breaker should be off as long as you are on the load side. And as stated when doing an IR test ALL SWITCHES SHOULD BE OPERATED.
 

Reply to Bit confused here, IR testing. in the Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock