2391 Testing Practical Exam

[Belter]

Hi guys, My name's Lee. I'm a spark currently located in Bristol.

I have my testing exam scheduled for 01/03/2011. A guy at work who did the test at the same centre as me showed me a photo of the rig which I have drawn in Illustrator.

Please see attached.

Can anyone give me any tips? My lecturer keeps contradicting himself.

Does the sub-main need to go on a separate sheet? A Continuation sheet? And if so what do you put down for Ze on the continuation sheet as the Ze you measure there isn't really Ze.

Also with IR, can you test from the main board to the sub-main (Isolator off) and then from the load side of the sub-main onwards (isolator off and dimmer switch linked out) and add them together? Or does this count as a 'parallel' part of the circuit and need to be calculated 1/RT = 1/R1 + 1/R2?

Can I do the same thing with the Direct Online starter? Test to the starter and then back from the Three Phase socket?

Thanks guys

Lee

 

[ADS]

Hi mate,

Hi guys, My name's Lee. I'm a spark currently located in Bristol.I have my testing exam scheduled for 01/03/2011. A guy at work who did the test at the same centre as me showed me a photo of the rig which I have drawn in Illustrator.

Please see attached.

Can anyone give me any tips? My lecturer keeps contradicting himself.

Does the sub-main need to go on a separate sheet? A Continuation sheet?

We put the circuits from the single-phase DB on the same sheet, but in the bottom 3 or 4 lines

And if so what do you put down for Ze on the continuation sheet as the Ze you measure there isn't really Ze.

It's Zs of the sub-main circuit and this is recorded as such within the 3-phase DB circuits. (if that makes sense.

Also with IR, can you test from the main board to the sub-main (Isolator off) and then from the load side of the sub-main onwards (isolator off and dimmer switch linked out) and add them together? Or does this count as a 'parallel' part of the circuit and need to be calculated 1/RT = 1/R1 + 1/R2?

You're IR testing, so no need to add anythng together.

Do as you said for the sub-main feed (DB2 isolator open), then test on outgoing sides of MCBs to N & E.

Our dimmer was on a radial off the three phase board, not DB2 - but, yes, you'll need to remove it and link it out.

Can I do the same thing with the Direct Online starter? Test to the starter and then back from the Three Phase socket?

Yes

Thanks guys

Lee

My BLUE

To be honest, I'm not sure about the 'using the same test-sheet' part......we might have used a seperate sheet for each DB, as you would in the real world - I just can't remember........but the other info should be ok:^O

 

[Ali]

In the paper work that I was given, I was told to do a PIR for the whole installation inc both boards, a shedule of tests to include both boards but a separate shedule of test results for each board - silly really but that's what they wanted.

 

[ADS]

In the paper work that I was given, I was told to do a PIR for the whole installation inc both boards, a shedule of tests to include both boards but a separate shedule of test results for each board - silly really but that's what they wanted.

Yes - and they call it a PIR, because it's supposedly an existing installation, but they expect you to test it like it's an initial verification - in other words, they want all the tests done - no 'sampling' or skipping unneccessary tests.

For example - on a 'real' PIR, you might IR test using all 'Live conductors' connected together and testing to earth.

On my 2391 he wanted to see the full 10 point IR test (3-phase).

This is understandable, because they want to be sure that you know how to perform every test - the only allowance is that you can perform the tests in the order that suits you.

 

[Ali]

I think the paper work said something about being able to isolate the installation for a certain amount of time at the beginning of the inspection and test, so you have to do the dead tests first.

When I did my practical, I found a thread started by Mr T very useful especially post 13. He started it on 5th March 2010 and it's called 2391 exam. I'm afraid I don't know how to show a link to it, but I'm sure you can find it using the search function if you think it might be useful.

 

[ADS]

I think the paper work said something about being able to isolate the installation for a certain amount of time at the beginning of the inspection and test, so you have to do the dead tests first.When I did my practical, I found a thread started by Mr T very useful especially post 13. He started it on 5th March 2010 and it's called 2391 exam. I'm afraid I don't know how to show a link to it, but I'm sure you can find it using the search function if you think it might be useful.

Think I Isolated, removed cover, confirmed safe isolation, then did Polarity, Ze and PFC while I was there - then on to the dead tests.

 

[Belter]

That's a good idea. It doesn't follow the order of tests but as it is an existing installation I'd assume that's ok? You could also do Phase Sequence whilst you were there?

---------- Post Auto-Merged at 20:55 ---------- Previous post was made at 20:54 ----------

Also one of the circuits is MICC where they are using the Sheath as CPC. What do I put down on my test schedule. MICC? and for SWA do I put SWA?

---------- Post Auto-Merged at 20:59 ---------- Previous post was made at 20:55 ----------

Also ADS you mentioned it's IR so no need to add anything together? So you get the two results from each end of the circuit and record the lowest?

 

[a1]

Ali,

Here is the 2391 Exam thread - but post 13 is from "The Doctor" not "Mr T" - TD is a 2391 Lecturer.

http://www.talk.electricianforum.co.uk/student-learning-zone-c-g-2330-levels-2-3-c-g-2381-c-g-2391-other-co/8803-2391-exam.html

 

[Ali]

Oops sorry. So many clever people on this forum I get confused:Blushing

 

[a1]

Oops sorry. So many clever people on this forum I get confused:Blushing

And at 23, so are you.

 

[ADS]

Ali,Here is the 2391 Exam thread - but post 13 is from "The Doctor" not "Mr T" - TD is a 2391 Lecturer.

http://www.talk.electricianforum.co.uk/student-learning-zone-c-g-2330-levels-2-3-c-g-2381-c-g-2391-other-co/8803-2391-exam.html

Cheers for that, Admin, I posted quite a bit in that thread and, to be honest, forgot half of it.

It was a nice little reminder of my 2391.

 

[rossi46]

does anyone know what the 12 faults are on the first visual test?

 

[NozSpark]

Come on rossi,,

Do you want us to do it for you?

The answers will be right before your eyes

IIRC I found 12 faults before I removed the CU cover

 

[Doc Hudson]

does anyone know what the 12 faults are on the first visual test?

Hello Rossi46, I would just put on record that Noz is not been harsh or sarcastic here. As it would be very unprofessional for a forum such as this to give quick list answers for people to memorize to pass an exam without attaining basic underpinning knowledge. If a person cannot identify the faults on a test rig, they will struggle in the real world inspecting a property for a landlord, or a new homeowner, or a small business office, or a 3-phase manufacturing plant. If unable to identify electrical hazards you could put other persons in danger. Any electrician competent enough to do a PIR will have no problem identifying the test rig faults. You just need keep a calm logical approach and just look at each circuit as a small part of a larger task and not panic, then I am sure you will soon find your way through, When are you taking the practical?

Doc H.

 

[NozSpark]

and I did mine in 2004...

It's things like IP ratings, incorrect errection methods, incorrect labelling,,,, stuff like that

And in all honesty this is the easiest of all the practical tests that you'll do,, like doc says take it one bit at a time and be methodical and you'll do ok.

 

[rossi46]

10th May is the practical.

I am a builder who has done a lot of electrical work for someone when I have been quiet, so no inspection or testing experience, just installation, mostly new builds and extensions or rewires, but all domestic. Have done the course, read the books and understand fully everything I have learnt, have bought a metrel tester and familiarised myself with that on my wiring at home. My concern is my lack of testing experience, what to look for etc, have never done anything with 3 phase, and things like listing conductor sizes. I can list twin and earth sizes easily, but think I will struggle with single core cable sizes as not used them. College were not great, 8 out of the 10 weeks were in the classroom, week 9 and 10 we werent shown anything, just told to go play in the booths! Tutor did not know how to do RCD test with Metrel tester, and the college didnt have a phase rotation tester but we are eexpected to use one in the exam!

I really could do with going some place and having a day doing mock practicals, just dont know who or where to go. I agree, I dont want answers handed on a plate, if you cant think for yourself you shouldnt be doing the job, but just want an idea of things, everyone on the course tells me its the hardest qualification you will do as an electrician and am just trying to be prepared.

 

[Zeespark]

Rossi, if I were you, I would do the 2392 first, teaches you the fundamental stuff.

Andy

 

[steptoe]

Rossi46, you need to up your game and get that ducati moving buddy.!!!!!

but on a serious note,

the faults you are expected to find are really very obvious and quite easy, IIRC our class had about 60 or 70 faults in total, the tutor stopped us at 12 each as the boards were also used for the learners and had lots of faults on them, then when we had each reached the required number of faults we were told what faults to actually put down on paper.

dont know if its still like that, but its not mega difficult to see the actual faults.

 

[rossi46]

lol

thats why i am doing the 2391, so when ducati sack me i got somewhere to go!!

 

[rossi46]

If the three phase circuit is a motor circuit rather than a socket outlet, zs can be calculated, but with the phase rotation test as its a live test, is it right that the motor will be running when you test for phase rotation at the motor. Also do you test at the dist board, the motor control/starter and the motor?

Also, having done nothing with 3 phase or motors. is there anything complicated about the inside of the starter? I have been told to tell the assessor to push the contactor in with a screwdriver, although i was thinking of putting a link across when i do my r1+r2

any help is appreciated