2391 March Completed

[vernam616]

Came out of the March 2012 exam liteally 30 minutes ago, anyone done it? How did you find it?

 

[acowx]

For the circuit breaker 3 * current I put


-Risk of fire due to the explosion
-Power loss for a period of time due to partial rewire or board change

forgot what I put after that.

 

[chronyx]

Yes 20C means no correction factor so just x 0.8

 

[chronyx]

I took the continuity of that swa lighting circuit as single phase though but can't remember of it was a three phase circuit!?
Good luck lads

Did you pick up on the swa providing the cpc as it was a two core cable?

 

[tex431]

Yep, I did. What about nulling test leads for the continuity test? Some people on my exam never. Oops

 

[LVSparks]

I took the exam last night, i have a copy of it as well! Good luck every body that took it

Found it resonable. Heres my answers to dodgy questions in part A

Q2 - List 3 specific items of info regarding dnos equipment, made available to person doing an inital verification? Earthing arrangements, supply protective device charactersitics, and nominal voltage Uo

Q4 - 3 items to check when inspecting the erection and termination of new mineral insulated cables? no swarf in pot, insulation to outside of cable, no mechanical damage to outside (wasnt too sure on these answers)

Q6 b) - state two of the outcomes to be recorded following the successful completion of the continuity of ring final circuit test? continuity of ring final circuit conductors, and R1 + R2

Q7 - 3 tets following earth electrode for TT? earth fult loop impe, pfc, rcd testing

Q8 - one point connected to MET by cpc? socket
by main protective bond? metalic water pipe
earthing cond? distributors earthing facility

Q 11 - an insulation resistance test is to be carried out on a single phase 230v circuit supplying socket outlets with integral surge protection?
insulation resistance tester, 500v dc, 1.0 Mohm (it appers 500v dc is wrong)

Q 13 - a test is too be carried out between live conductor of a selv circuit and the conductors of a 400v 3 phase motor circuit to confirm electrrical seperation? insulation resistance tester, 500v dc, 1.0 M ohm

Q 16 - an earth electrode resistance test is to be carried out on an electrical installation, forming part of a TT system, using an earth fault loop impedance tester. State the action which must be taken prior to carrying out the test with regards to the-
supply to the installation - isolate from the installation
earthing conductor - disconnect from MET
and the action to be taken regarding the earthing conductor once a measurment has been made - subtract reading from result

Q 20 - state 3 possible consequences of a circuit breaker interuppting a fault current 3 x larger than its rated breaking capacity? it will be unusable again, it could cause a fire, it may cause damage to property and equipment


Let me know what you all think please

 

[Ben Grant]

I applied the rule of thumb (0.8 factor) but I got unsatisfactory - satisfactory - unsatisfactory - satisfactory.

Can anyone remember the scenario

these were the max values and these were the recorded max values as per 0.8
2.87.........2.4........2.29
2.3..........1.9........ 1.84
1.44........1.25........1.15
0.92........0.61........0.73

first column is max values, second is recorded, third is tablulate

what circuits would pass, which would fail, show workings, say pass or fail

 

[vernam616]

First 3 failed and last one passed

Very interested in getting a copy of the exam paper

 

[CRAWSH]

In the Notes below Table 61 of BS7671, it clearly states the following:
Where surge protected devices (SPD) or other equipment likely to influence the verification test, or be damaged, such equipment shall be disconnected before carrying out the insulation resistance test. Where it is not reasonably practicable to disconnect such equipment (e.g. fixed socket-outlet incorporating an SPD), the test voltage for the particular circuit may be reduced to 250V d.c., but the insulation resistance shall have a value of at least 1Mohm.

 

[i=p/u]

i think i have passed,, the amount of effort i put in comming upto exam, id be suprised if i didnt..


one question that concerned me was about mineral insulated cable, i put bending radius, pot securely fixed and insulation resistance checked before making of pot,, something along them lines

 

[i=p/u]

but that was a guess, ive also heard people are putting straight in for the next exam without knowing results

 

[i=p/u]

good post/thread

 

[dhh]

I put bending radius not exceeded, gland pot sealed and sleeved conductors, the zs question I thought was pass pass pass and the last one failed. Am I wrong thinking u take 80 percent of tabulated value and the measured zs has to be Lower than this 80 percent value, as we want zs to be as low as possible? Anyone? hope I didn't balls the last question up rushing so I could go over my other answers :/

 

[hearts]

The question about finding R1+R2 for car park lighting circuit, what did everyone answer regarding the contactor.....did anyone link the line conductor ?

 

[dhh]

Yeah I put link out contactor and time switch

 

[chronyx]

The question about finding R1+R2 for car park lighting circuit, what did everyone answer regarding the contactor.....did anyone link the line conductor ?

Yes I mentioned that too, said to bridge it. Think a couple of questions I messed up now I see what others put. But think I did OK. MIMS question threw me, not touched it since one afternoon at college in 2009