2391 exam question

[john h owen]

The owner has agreed that the whole installation may be isolated in order for tested to be carried out.There is a period of 1 hour allocated for this work.List the test that MUST be carried out during this period(individual circuits may be isolated after this period)

 

[Guest123]

I would have said Ze was most important???

 

[Sparky Ninja]

What a strange question.

Off the top of my head... Continuity of bonding conductors, site supply characteristics (ze, psc/pfc) and maybe RCD if it's a TT or something.

Questions like this that create a purpose to deviate from the correct sequence tick me off.

Oh and possibly polarity on the incommer main switch.

 

[Guest123]

Good old city and guilds........confusion personified.

 

[WayneL]

What a strange question.

Off the top of my head... Continuity of bonding conductors, site supply characteristics (ze, psc/pfc) and maybe RCD if it's a TT or something.

Questions like this that create a purpose to deviate from the correct sequence tick me off.

Oh and possibly polarity on the incommer main switch.

But there isn't a 'correct sequence' on a PIR - you can test in any order that you like.

I would want the whole installation isolating for the majority of my testing, so I'd get done whatever I could in that time.

I wouldn't worry too much about Polarity, PFC and RCD testing - but they only take a minute anyway - but I'd want to get any other testing done that involves poking around in the CU.

 

[CRAGS]

Oh I remember that bad boy from the June exam!!!!! Believe I may have listed the dead tests I.e. Cpcs insulatin resistance etc????

 

[brucelee]

hi mate
I would put
continuity of protective main and supplementary bonding conductors
insulation resistance
external earth fault loop impedence( Ze)
prospective fault current (pefc) (pscc)

the continuity of protective conductors
continuity of ring final circuit conductors
polarity
earth fault loop impedence (Zs)
rcd testing can all be carried out after the 1 hour allocated time
any way think thats what i put in the june exam

 

[Guest123]

The owner has agreed that the whole installation may be isolated in order for tested to be carried out.There is a period of 1 hour allocated for this work.List the test that MUST be carried out during this period(individual circuits may be isolated after this period)

The way I read this is that your permitted a shutdown for one hour to carry out some testing, it states that other circuits can be isolated after this period so the main one for me is Ze as we need to disconnect the MEC.

This is the age old problem with C&G, they word things in a manner that convalutes 10 different answers!!!!

 

[Sintra]

Agree with Lenny

 

[brucelee]

I agree to with lenny
you have to read the questions a few times as they word it badly and you can easily answer incorrectly through not reading and understanding before answering good luck mate keep revising and take your time when answering I was rushing and finished in 1 hour 40 mins then looked about and everyone was still writing so i went over it all about three more times and found one question number 17 that i read completly wrongly so crossed out and put a note saying please go to end to see q17 lol must have worked as i passed first time and I had no experience of testing 3 phase but learned over the four months of study every day all day and im not joking its not easy but if you put your mind to it and your determined its possible Good luck to John

 

[nickblake]

I agree with lenny

 

[Sparky Ninja]

But there isn't a 'correct sequence' on a PIR - you can test in any order that you like.

I would want the whole installation isolating for the majority of my testing, so I'd get done whatever I could in that time.

I wouldn't worry too much about Polarity, PFC and RCD testing - but they only take a minute anyway - but I'd want to get any other testing done that involves poking around in the CU.

Where was PIR mentioned?

 

[Sparky Ninja]

The way I read this is that your permitted a shutdown for one hour to carry out some testing, it states that other circuits can be isolated after this period so the main one for me is Ze as we need to disconnect the MEC.

This is the age old problem with C&G, they word things in a manner that convalutes 10 different answers!!!!

If it was a single test answer then ze would be the first consideration. But how about continuity of bonding conductors? To carry out the test it would need to be disconnected at the origin, therefore all circuits should be isolated while the test is carried out?

 

[WayneL]

Where was PIR mentioned?

If it's not a PIR, then it's an 'Initial Verification' and wouldn't be energised until the testing had been done anyway - so you wouldn't need the 'one hour' shutdown.

If the owner is allowing you one hour to shut the thing down, then it must be an existing installation, so PIR.

The only time the tests are required to be done in the stated order are during 'initial verification'.

 

[wacko]

Hi chaps,

Dead tests and visual checks I'd say. So Ze and IR of the whole installation. Any faults can be checked by isolating circuits later.
But with the dead tests - that's getting the fingers into the board and checking connections etc.

Regards