2391-52 practical exam help

[H]

Everyone on my course had three faults

 

[H]

On the practical, we were told not to look for any visual faults as this was covered doing the photo exercise. My faults were high protective bond reading, open circuit on the lights and low IR.

 

[remedial]

Last fault was on the ring circuit basically the conductors were all 2.5 L&N came back at 1.23 the cpc was 3.56 straight away this was noted meaning that our calculated zs would be to high so been recorded as a C2

good info mate. just wondering why its a C2? was there an RCD on the circuit?

 

[Deleted member 26818]

I think I only had two faults when I did mine?
There were 6 or 8 switches that the invigilator had to choose 2 to switch.
Each switch produced a single fault.

 

[Ian1981]

That’s it all complete PASSED.
Basically had 3 faults
my main bond was one of the faults giving a reading of 4.56 should be 0.05 or below

Next fault was the earthing conductor from the starter at the load side was broken basically you do a r1+r2 test to the top of the starter note it then at the bottom and add together for the total r1+r2 so from the load side it was broken so could not calculate zs as a result of this.

Last fault was on the ring circuit basically the conductors were all 2.5 L&N came back at 1.23 the cpc was 3.56 straight away this was noted meaning that our calculated zs would be to high so been recorded as a C2

Then paper work had to be perfect so happy it’s out the way and onto a new course thanks for the help appreciate it.

Well done on passing but why should the R2 reading on the continuity of protective conductors be 0.05 ohms or below?
Guidance note 3 makes it clear that this reading is between 2 exposed conductive parts such as pipes and not from the MET to the bonding conductor.
It’s an urban myth badgered around the industry and taught incorrectly by the tutors

 

[Deleted member 26818]

I always took that 0.05 Ohms to mean the continuity between the conductor and the extraneous conductive-part.
Not the resistance of the conductor.

 

[Ian1981]

I always took that 0.05 Ohms to mean the continuity between the conductor and the extraneous conductive-part.
Not the resistance of the conductor.

Agree but the apprentice at work is taught and from what I read on other sites is that the resistance from the MET to the extraneous conductive part (or the protective bonding conductor) must not be greater than 0.05 ohms, which is the wrong advice

 

[L1Jay1]

Just taken 2391 practical and failed it , my brain stopped functioning , didnt realise i was going to find it that difficult , normally testing isnt a problem for me. Was told on exam that i only needed to test one lighting circuit , the was a one way and a two way lighting circuit . couldnt work out which circuit was which , not marked up on board or at DB .

 

[JBW175]

Just taken 2391 practical and failed it , my brain stopped functioning , didnt realise i was going to find it that difficult , normally testing isnt a problem for me. Was told on exam that i only needed to test one lighting circuit , the was a one way and a two way lighting circuit . couldnt work out which circuit was which , not marked up on board or at DB .

Sorry to hear you’ve failed. surely you should have picked it up when dead testing continuity? And the cable size & MCB size should have given a good indication of the circuit?

when I did mine, I’m sure one of the faults on the rig was no continuity at one of the battens when R1R2 testing of the lighting circuits.

 

[whiteelectrical]

lightmates are a brilliant idea.pity they won't work with megger leads.

I think they work with Meggers if you reverse the leads

 

[whiteelectrical]

lightmates are a brilliant idea.pity they won't work with megger leads.

I think they work with Meggers if you reverse the leads