Problem of the week

[Guy]

The forum is full of questions but they are commonly asked by electricians and answered by very experienced electricians and often to fully understand the answers a high level of proficiency is required and the comments coming from different sources can make the thread difficult to follow.As a student/mate/improver would you be interested in a weekly 'electrical problem' set by one of the 'old hands'? I appreciate that we have old exam papers but the questions in the most part do not relate to real life scenarios.

If you would be interested in using this as a learning tool (and actually doing it as someone would be giving up their time to construct the question) please leave a message below as if there is little interest no one will volunteer to set the problem. Are you an experienced electrician and would you construct a problem and give a definitive answer a week later? No marking of answers would be required as people could do that themselves. Any opinions and suggestions on this idea are welcome.

 

[m4tty]

This was done a little while ago I think but the problem set was way too hard lol good idea tho which gets the brain thinking

 

[Andy™]

it was tried a while back, i think there were only 2 threads made

 

[Manator]

It is a very good idea Guy, and one that has been posed before. I think a few members did get involved people like Sidewinder, Canoeboy and a few others who gave some easy intermediate and difficult calculations or example for people to work through. We could possibly do something similar and have a thread dedicated for such things.

 

[Guy]

ok, but if has been tried before then maybe it would be 'flogging a dead horse'. Lets see what the response from the student/mates/improvers is like.

 

[roys]

I think it is a good idea, strange I don't remember it being done before. I have several industrial type questions at the ready if required / wanted.

 

[steptoe]

I was actually thinking of doing something similar along the lines of 'uncle Albert's tip of the week'

but then I realised I didnt actually know enough for that to be viable.

I take it you mean a problem/fault, rather than just some simple calcs,

something along the lines of,

3 bed house, 2 ring finals and 2 lighting circuits, imm heater redundant circuit still installed but untraceable,when landing light is turned on loft light glows dimly, when hall light is turned on and landing light still on loft light works correctly,

loft light works correctly when landing light is off, regardless of any other lights.

what tests should be performed to determine the fault.?

ish kinda thing.

 

[Guy]

Exactly steps, just that kind of thing. Not one single reply so far from anyone interested in working on the problems though which is disappointing but it is only the first day. Your example question immediately highlights one of my weaknesses as I have no instant thoughts in my head but I know I can 'get it' and thats what I want to improve. Im off to have a think about fault.

 

[danmoriarty]

I'd definitely be interested in this, there's still so much to learn

 

[gavindrummond]

That sounds like a brilliant idea. I'm a student and would really like it

 

[steptoe]

well,

there you go guys,

solve uncle Alberts problem and it'll save me having to do it tomorrow!

actually, it was a few weeks ago and its sorted now, remember, not everything is always relevant, nor have I added any red herrings,

I have simply put down exactly what I faced on having a quick check on the problem, oh, no fancy fittings or energy savers were responsible,

the installation of the loft light may be questionable though.

all I need is ideas as to what may be the cause, or what you would first look for/test.

 

[Jono Pashley]

First i would test the operation of their kettle and test the coffee was upto standard

 

[Maplasterelec]

I think it's a great idea, keeps the brain ticking over. Is the loft light getting some power from a neutral maybe?

 

[Manator]

OK we now have our first problem of the week, this was posted by Steptoe and he will be giving the pointers for this weeks problem.

At the end of the week Steptoe can reply to all who have had a go, and tell you how he solved the problem.

The problem.

3 bed house, 2 ring finals and 2 lighting circuits, imm heater redundant circuit still installed but untraceable,

when landing light is turned on loft light glows dimly, when hall light is turned on and landing light still on loft light works correctly,

loft light works correctly when landing light is off, regardless of any other lights.

what tests should be performed to determine the fault.?

well,

there you go guys,

solve uncle Alberts problem and it'll save me having to do it tomorrow!

actually, it was a few weeks ago and its sorted now, remember, not everything is always relevant, nor have I added any red herrings,

I have simply put down exactly what I faced on having a quick check on the problem, oh, no fancy fittings or energy savers were responsible,

the installation of the loft light may be questionable though.

all I need is ideas as to what may be the cause, or what you would first look for/test.

Thanks to Steptoe for the first problem of the week, it would be good guys if we only have one topic per week, so if anyone as any more ideas please wait until this problem is solved.

Thank you.

All text taken from steptoe's above posts

 

[ams13]

This is a good idea.

Ill have a go steps. I have very limited fault finding experiece,

I would probably start with a continuity test of both the light circuits first..

 

[steptoe]

well thats a start, but prob not the first test to be carried out,

I am actually going to have to think about the proper testing procedure for this fault, as the method I used is not a recognised one and not one I could endorse on a public forum.

a continuity test is deffo in there, care to elaborate on continuity of what?

 

[ams13]

Well I would start with L-E and I was going to say of the faulty light circuit. I would need to find which one first so I suppose I could try switching one off at a time before continuity and see what happens.

 

[sprocketflup]

as the method I used is not a recognised one and not one I could endorse on a public forum.

you licked it didnt you?

check for continuity between the loft light and the 2way landing lights?

 

[Maplasterelec]

Find out which circuit the loft light is on. Isolate it (safely) and test continuity of live and neutral to see if it is borrowing a neutral from the landing light

 

[steptoe]

OK, I need to present this in a better manner, here goes,

3 bed house, 2 ring finals and 2 lighting circuits, imm heater redundant circuit still installed but untraceable,when landing light is turned on loft light glows dimly, when hall light is turned on and landing light still on loft light works correctly,

loft light works correctly when landing light is off, regardless of any other lights.

what tests should be performed to determine the fault.?

no low energy lamps of fancy fittings are at fault/to blame,

consumer unit has NO RCD, all MCB OCPD circuits, house was built early '90s,

landing light intermediate switching, DS hall light 2 way switching, all other lights normal 1way,

loft light questionable installation,

2 smoke alarms 1 up one down.

I think that is all that is really relevant[or not], Im not trying to trick you, just want you to think what may or may not contribute to the problem,

what is the first thing you would actually do after the customer explains the fault?

---------- Post Auto-Merged at 22:16 ---------- Previous post was made at 22:13 ----------

Find out which circuit the loft light is on. Isolate it (safely) and test continuity of live and neutral to see if it is borrowing a neutral from the landing light

good idea, but why do folks always think of borrowed neutrals? it wouldnt make much sense on a loft light to extract a line from the downstairs circuit and a neutral from US...