Fault finding

[YoungSparky]

Hey all,

Im a college boy so excuse me for my dumbness lol. But as this is the only thing i can think of for help (as im on easter holiday) i'll be asking a question i dont understand, well i do but can't put it into words and diagrams ect.

Anyway, i will be forever greatful to those who can answer the following question(s);

i) With the aid of sketches describe how you would test to identify and locate the following faults;

a) reverse - polarity at an ES centre contact lamp holder

b) sockets 5-8 of a radial power circuit containing 8 socket outlets do not function - open circuit in the neutral conductor

c) short circuit on cable leg between S/O 4 and 5 on a ring final circuit (RFC) containing 12 socket outlets

d) immersion heater circuit 16A mcb tripped and will not reset

e) over-sensitive RCD


Thanks again, i will be again forever greatful if some get answered.

 

[Spark123]

Has college not started back yet? Our local one started back on Monday.
a) you would pick this up doing the R1+R2 test as part of initial testing.
R1+R2 should be in your text books, on site guide, guidance note 3.

b) You probably wont pick this up in initial testing however once you know the sockets aren't functioning you could do a Rn+R2 test and it will pick up where it is.
Basically join N&E together for that circuit only at the CU end and then test N-E on low resistance at each socket - you should see a low resistance up to the point that the break is then infinity afterwards. Gets it down to two sockets.

c) A case of using an Insulation Resistance tester and shortening the system down, possibly using the half split method.

d) isolate, disconnect heater and insulation resistance test to earth. Low resistance test across the element to see if it has a resistance.
If the element is OK then test the circuit feeding it and see if the MCB will reset without power.

e) Bog standard RCD testing as in the on site guide or GN3.

 

[YoungSparky]

Oooo, Nice one mate!! Appreciate it! Thanks for the quick reply.

In answer to your question, no it hasnt lol i go back this Monday coming, i think easter is too long tbh, but oh well, im not complaining

 

[Taylortwocities]

i think easter is too long tbh,

If you have time on your hands you should have got out and read your On Site Guide or gone to the library to research those basic questions. That way you could have found out the answers for yourself. A much better way to learn! IMHO.

Oh yes, and lol to you too.

 

[studentspark]

I know what you mean about college, you practically have to drag any information from the teachers

I find this quite useful

http://wiki.diyfaq.org.uk/index.php?title=Category:Electrical

 

[TicklyT]

I know what you mean about college, you practically have to drag any information from the teachers....

IMO that's how education works - you learn how to find, understand and interpret the information you need yourself.

If you are given sets of facts to learn by rote, without questioning the source or validity, it's training.

 

[Taylortwocities]

I find this quite useful

http://wiki.diyfaq.org.uk/index.php?title=Category:Electrical[/QUOTE]

I would be very worried about the plugs shown on that web site.

You'll find that info ( and a lot more) on THIS SITE. See the WIKI //www.diynot.com/wiki/electrics

and also in the reference section //www.diynot.com/forums/viewtopic.php?t=7553

 

[YoungSparky]

Ok, thanks everyone for there own opinion on learning lol

 

[YoungSparky]

Just wondering, is it best to look for an apprenticeship with a small company with 1/2 people, or a larger company covering many areas?