tonights 2391 exam....(10th march 2011)

[lynj]

one thing to say and that is did c&g forget how to be staightforward? felt like some of the questions were half thought......

anyone else take it?

 

[Paul.M]

May I also say welcome to all the new members on this thread. Stick around you might just like it?

 

[Paul.M]

functional test
press the test button on the the protective device (RCD) to check correct operation of the mechanical parts are working correctly

The 8 marks question was to describe the rcd ramp test including time, mA and and if it would "activate the device". I also included the current wave for all 6 tests . The question after for 2 marks I think was asking for functional testing of the test button and for the rcd switch.

 

[Paul.M]

With the ir test isn't it best to just quote the test as in gn3? I.e. Make reference to removing any voltage sensitive equipment or link out where applicable and not leave out steps based on the fact your just testing the swa?

The way I read the question on IR test of the new lights that has an isolation switch at the base if each pole is to open the switch, link L+N and test to cpc? The swa armour was not being used as the cpc, it was a 4 core single phase and one of the cores being used ad cpc.

Next year at this rate we will all have to past a CSI course to be able to decipher the scenario never mind the bloody questions! I'm sorry C&G but not everyone has a university degree in English to be able to understand your questions. Saying that, if you put these students of the 2391 infront of the scenario you mention, 80%+ would pass because were electricians and not a Masters in English literature.

 

[john25]

Right for question 21 it asked how many certificates would be issued for the Marina and other buildings .So I put A PIR for the main Building and a schedule of inspections and schedule of test results for each of the buildings. and a EIC with a schedule of inspections and schedule of test results for the new circuit.

Question 26 didn't ask for ask for a disconnection time for the RCD tests if I remember correctly just the test current

 

[russty]

Q.a) In the shower unit, what visual inspections can you do to the c/u (4 marks)

B) explain answear to "a" (4 marks)

Mine was:-

* Any burnt or overheating cables
* Any damage to the CU affecting its intregrity
* Any missing grommets
* Any missing blanks on any spare ways

Fairly stright forward reasons for my answers i thought

 

[john25]

For that question I put Damage/Labels/correct connection of conductors and Damage to IP integrity of the DB.

 

[NMc]

Would be interesting to she the exam paper as people are remembering questions differently

 

[I am Sparkacus]

Q. Draw a diagram of a fault to earth from an office socket including labels. (15 marks)


How did people draw this? I drew 3 phase transformer, distribution board, and socket outlet. It did not state any other boards inbetween 3 phase board and radial circuit. The fault path ran along point of fault at socket, through cpc conductor labelelled r2, into MET, down earth electrode, through ground, up transformer electrode, to centre point of star transformer, with neutral connected here tool, up l1's winding, through line of supply cable, to consumer unit, through protective device, then along circuit line conductor labelled r1.
How far off the mark am i?

 

[I am Sparkacus]

Originally Posted by paul.m
Q.a) In the shower unit, what visual inspections can you do to the c/u (4 marks)

B) explain answear to "a" (4 marks)

-Correct current carying capacity of cable for protective device
-Correct order of neutrals and earths connected
-RCD present
-Damage??
??

I think I have flunked this exam, wish i was a plasterer, they dont have ever changing regs, and mathematical ******** to learn!!

 

[GrannySmiff]

Whats the two things you can ONLY find out from the DNO?

 

[russty]

Whats the two things you can ONLY find out from the DNO?

Got me thinking this one, had a stab at external earth loop impedance Ze and type of earthing supply TNC-S/TT/TN-S

 

[russty]

Q26. What 2 types of Inspection & Test for confirm for voltage drop?

Went for PSCC and PEFC, dont know if this was right carnt seem to find it in GN3 to confirm?

 

[IQ Electrical]

Q26. What 2 types of Inspection & Test for confirm for voltage drop?

Went for PSCC and PEFC, dont know if this was right carnt seem to find it in GN3 to confirm?

How about measurement and calculation?

You can physically measure the voltage drop or calculate it from cable length/size/load

 

[IQ Electrical]

Q26. What 2 types of Inspection & Test for confirm for voltage drop?

Went for PSCC and PEFC, dont know if this was right carnt seem to find it in GN3 to confirm?

How about measurement and calculation?

You can physically measure the voltage drop or calculate it from cable length/size/load

 

[IQ Electrical]

Got me thinking this one, had a stab at external earth loop impedance Ze and type of earthing supply TNC-S/TT/TN-S

If it said 'only from the DNO' then it's something you can't measure or visibly confirm so it has to be from the characteristics of the sealed supply fuse eg. BS, type, rated current and short circuit capacity.

I suppose you could get away with supply frequency.

 

[Paul.M]

Q.a) In the shower unit, what visual inspections can you do to the c/u (4 marks)

Unless I misinterpreted the question I believe it was a visual without taking the front panel off so I put i) damage, ii) labels, iii) correct size rcd, iv) correct size mcb. These are the things that we do naturaly without thinking, like tying your shoes laces but try and describe in writing how to do it?

 

[russty]

How about measurement and calculation?

You can physically measure the voltage drop or calculate it from cable length/size/load

Just couldnt think of anything else!

 

[john25]

If it said 'only from the DNO' then it's something you can't measure or visibly confirm so it has to be from the characteristics of the sealed supply fuse eg. BS, type, rated current and short circuit capacity.

I suppose you could get away with supply frequency.

I went for Ze and Maximum demand on that question

 

[john25]

Q.a) In the shower unit, what visual inspections can you do to the c/u (4 marks)

Unless I misinterpreted the question I believe it was a visual without taking the front panel off so I put i) damage, ii) labels, iii) correct size rcd, iv) correct size mcb. These are the things that we do naturaly without thinking, like tying your shoes laces but try and describe in writing how to do it?

It was a Visible check mate thats why I went for Damage/ labels Correct connection of conductors and damage to IP integrity of the DB

 

[johnmcbride]

There was a question at the start, what 3 tests would be carried out first on a three phase supply to (can't remember what it was but I had never heard of it)?