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MrTrance

Hi, as you already might know, I have just started my 2330 level 2 course.

I have quite a few questions which need answering, I have my BS7671 book but the answers arn't really clear.

1. I don't quite understand amperes, are they connected to the voltage in the mains? E.g if I have 50 volts I have 5 amps and if I have 25volts I have 2.5amps? Is that correct, I no voltage is the type of current which passes through copper conductors but I am not clear on amperes and how they link to voltage.

2. I don't understand what is meant by the word BOND or BONDING, what I do no is that it has something to do with conductors?

3. Earth!!! I am not clear on the Earth conductors job, does it carry the same amount of current as L + N? Also whats an earth loop and why is my double socket outlet in my bedroom got a connector on the earth cable?

If anybody can have a go in answering these questions, again I would really appreciate it, we have all got to start somewere and I wouldn't be wasting my night times studying if I wasn't interested in the course I CHOSE to go on in college.

Thanks a lot for you time,

Micky
 
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as far as i'm aware micky is a first day apprentice.how long have you been doing it micky?

can someone recomend him an easy read ???
 
Hi Micky,

First off what book are you looking at. Is it the 17th Edition BS7671 regs book?
How many weeks you been doing your 2330 course now and what have you covered so far?

Tony

Come on guys we've all been green at some time, Micky's just started his 2330 course, have a quick read of his introduction to find out a bit more about him. If he's trying to make sense of "the big red book" think about the threads and questions it's given us "experienced" sparks on this forum.

I second Wayne's comment, anybody know a easy read introduction book to recommend?
 
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Right I am doing full time course at college (no apprenticeship), the book I am reading is the small version of the big red book, the wiring regs.

I have been doing my course for 3 weeks and so far covered basics of wiring plugs, sockets, 1 way consumer unit, cieling roses, but mainly were doing all different organisations of electrical installtion (NIC etc etc).

Who is Micky Taker? and Paul, we all started somewere and if I can't ask some simple questions on an electrical forum without getting daft perfetic replies, then maybe you shouldn't be posting on it?

As for the rest of you, thanks a lot for your suitable answers, and Mr Spark Doctor, whats that Isbn code my friend?

Micky.
 
Mickey,

no problems with the questions, its just to do them justice what take a lot of typing.

I give my new starters the CITB Essential Electrics book (its code E14 on the CITB website). Is a good basic book that starts at very basic level, (series / parallel circuits etc) and moves through to bonding and earthing etc.

It would be better if you bought a book such as that, and tried to absorb it. Then when you have specific problem areas (and you will!) then come on and ask specific questions

Its easier to help/sort out your existing understanding, than try and give you the full bifta from scratch!

good luck:)
 
Now we know where you're at with your course and it would appear that you have the on site guide what I would suggest is have a look at the books Shakeey and Spark doctor have suggested (Shakey is highly experienced in both the electrical and electrical training industries and "the Doc" has a young apprentice working for him) so they both have a good knowledge of what is suitable. Use your on site guide to read up on what you have covered in your course lessons, if you are going to read it at all at the moment (I am not being sarcastic there) The regs and their on site guide are written to say what you should do and not always why you should do it so trying to learn from them can be very difficult and possibly frustrating for someone who is totally new to the industry.

Do not get disheartened by not understanding things at the moment, all will eventually start to fall into place and do not worry about asking questions on this forum. There might be some obtuse answers but you will find that we will give you either the answers you are looking for or where to find them. The latter is often the better as if you have to find the answer yourself you will never forget it.

Good luck with your course and keep asking questions.
 
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I am new to the trade and have just completed an intensive course with a view to gaining experience with an electrician. The best preperation I found was a book that became an invaluable reference throughout my studies. Ask for 'Basic Electrical Installation Work' by Trevor Linsley (ISBN 0-7506-6624-2). It`s matched to the requirements of C&G 2330. This should answer your queries in a logical order.
 
Hi, as you already might know, I have just started my 2330 level 2 course.

I have quite a few questions which need answering, I have my BS7671 book but the answers arn't really clear.

Not surprised Micky, it's not that sort of book. It's not designed as a textbook, it's a reference book before it's anything else. It would be a bit like me giving you a owners handbook for a Mondeo and then expecting you to go and build one then learn to drive it.


1. I don't quite understand amperes, are they connected to the voltage in the mains? E.g if I have 50 volts I have 5 amps and if I have 25volts I have 2.5amps? Is that correct, I no voltage is the type of current which passes through copper conductors but I am not clear on amperes and how they link to voltage.

The very first thing you need to get a handle on is this relationship between volts/resistance/current. The relationship between these three quantities is summed up in its most basic form in OHMS LAW. This quick analogy might help give you a mental picture of what's going on.

I learned it at school and the physics teacher referred to it as "the water analogy" and it was my 'penny dropping' moment.

Think of water flowing through a hose/pipe which is fed from a water tank with a basic ON/OFF valve to control the flow set on a platform. The pipe represents an electrical conductor and the water represents the flow of electrons moving through it. The tap in a water 'circuit' represents the role of the switch in an electrical circuit. (time for some jargon! sparks commonly abbreviate it to 'cct.')

OK that's the setup. Open the tap and water will flow through the pipe and out the end. With the tank a few feet off the ground if you place your thumb over the end it will be pretty easy to stop the flow because the pressure driving the water is so low (ie a garden water butt). if you raise the tank 20ft off the ground (like the hot water header tank in a house) you would feel a much stronger pressure, this is analogous to "VOLTAGE" basically 'electrical pressure'. Raise the tank a thousand feet above the outlet and the pressure would be impossible to contain with your thumb and it might even be dangerous to try it. You could call that a high pressure (voltage) system. That's a quick illustration of voltage.

What about resistance and current? With the tank back at a sensible height you tap a pressure guage and a flowmeter into the pipe before the valve. With the valve closed and no water (current) flowing the pressure guage reads full STATIC system pressure and no rotation from the flowmeter tells us that no current is flowing. You open the valve and water flows, if you look at the flowmeter you see it spinning at full whack as there is nothing to impede the flow of water (electricity) other than the capacity of the pipe (its cross sectional area in other words just like cables have cross sectional....sod it! c.s.a. (more jargon) This is analogous to a dead short in an electrical circuit.
You'd also notice that the pressure guage would barely read anything at all because the water (current) would much rather bypass the resistance of the guage's mechanism to take the easiest path (of least resistance) to freedom (earth) in order to equalize the system pressure in the butt with the outside world.
(If the water butt were a battery it would discharge through the pipe/conductor until no more water/energy was left. The pressure guage/voltmeter would slowly fall to zero and the flowmeter/ammeter would spin ever slower as the pressure driving water through it fell until it was drained.)

Now with the tank refilled and running stand on the end of the pipe and watch the two guages, you'll see that the flowmeter slows down progressively the harder you step on the pipe, less water (CURRENT) is flowing due to the resistance you've introduced. If you look at the pressure (VOLTAGE) guage you see that as you step on the pipe harder the needle rises. This roughly equates to voltage drop across resistances in an electrical cct. You could put a pressure guage on either side of your foot and work out how much pressure/voltge is dropped across that resistive part of the pipe/conductor due to your foot being there. hope you are beginning to get the idea how all the quantities (voltage, current and resistance) interact with each other?

In the electrical field the open pipe 'running to waste' isn't strictly correct but it serve the point. Instead of a tank and open ended pipe an electrical circuit is more like a closed loop of pipe and it derives its pressure not from a static header tank but a pump (a battery or generator in an electrical cct) in the loop. The bigger the pump and the faster it spins the greater will be the pressure (voltage) driving water (current) through the various points of use, valves, flow control devices, hydraulic kit (in electrical terms switches, resitances, transformers, amplifiers)

Its by no means a perfect analogy but hope that helps a bit.

2. I don't understand what is meant by the word BOND or BONDING, what I do no is that it has something to do with conductors?

3. Earth!!! I am not clear on the Earth conductors job, does it carry the same amount of current as L + N?

Back to the pumped water circuit idea. The pipe/conductor supplying energy to the device (line aka live) is L1 and the pipe taking the water from the outlet (neutral) equates to L2. What happens if one of the feed or return pipes were to spring a leak ie develop a fault in electrical parlance? Water everywhere! earthing is the electrical equivalent of putting a drainage guttering around each pipe so that any escaping water is immediately channelled safely out of harms way so that no damage results. Obviously that 'guttering' has to be big enough to deal with the worst case scenario such as the pipe (feed OR return) being completely severed. If that means of channeling (i.e. means of earthing) is insufficiently sized the water will overflow and damage result. So in normal circumstances there should be no voltage flowing down the earthing 'channel' (conductor) but it must at all times be ready and able to take the strain if a fault develops. Bonding is a bit like adding a bit of extra 'guttering'! my brain hurts now and I'm going to have a beer!

Also whats an earth loop...

I've told you my head hurts at the moment but if you really want I can see if I can find a post from an unrelated forum which should give you an idea. It's a big subject to jump straight into Mickey.

and why is my double socket outlet in my bedroom got a connector on the earth cable?
because the guy who did it was a f*cking tw@t who didn't know the first thing about the desirability of having the lowest Earth Loop Impedance (for our purposes impedance=resistance) possible.

If anybody can have a go in answering these questions, again I would really appreciate it, we have all got to start somewere and I wouldn't be wasting my night times studying if I wasn't interested in the course I CHOSE to go on in college.

Thanks a lot for you time,

Mickey

You won't be wasting your time geezer, I'm amazed at how many people are happy to sit in total ignorance surrounded by their electrical universe about which they know jack ****! Head down and keep asking till the penny drops.:D
 
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Who is Micky Taker? and Paul, we all started somewere and if I can't ask some simple questions on an electrical forum without getting daft perfetic replies, then maybe you shouldn't be posting on it?
Micky.

Ha ha ha! Nice one Micky :D

I've just started my 2330 L2 also mate. Don't be put off by the 'funny' comments. They're a nice bunch really :D

Hope to see more of you on here.

Not at Hull college are you?

Oh and Carter? Well put. Helped me.

Thank you.
 
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Who is Micky Taker? and Paul, we all started somewere and if I can't ask some simple questions on an electrical forum without getting daft perfetic replies, then maybe you shouldn't be posting on it
:mad: hold on a bit pal,who the feck are you to tell me what and when i can post you little ---- , you no know feck all about electric just the same as none of us did when we first started but i didnt bend everyones ear asking questions that even if they had told me the answers i wouldnt have understood them,instead i let the course progress and learned at a sensible pace ,so why have you got to get all the answers in the first foftnight? unless your the one that you allways get in class who likes to be able to put his hand up with all the answers for a pat on the back off teacher,so slow down and enjoy your first year because when the second year starts you will wish you was back in the first.:p
 
:mad: hold on a bit pal,who the feck are you to tell me what and when i can post you little ---- , you no know feck all about electric just the same as none of us did when we first started but i didnt bend everyones ear asking questions that even if they had told me the answers i wouldnt have understood them,instead i let the course progress and learned at a sensible pace ,so why have you got to get all the answers in the first foftnight? unless your the one that you allways get in class who likes to be able to put his hand up with all the answers for a pat on the back off teacher,so slow down and enjoy your first year because when the second year starts you will wish you was back in the first.:p

*Falls on floor laughing*

Good comeback PaulM!

*Ding ding*

"End of round 1!" :D


unless your the one that you allways get in class who likes to be able to put his hand up with all the answers for a pat on the back off teacher

Erm...That'd be me :eek::eek::eek:
 
Oops! did I say...
there should be no voltage flowing down the earthing 'channel' (conductor)
Sorry, voltage doesn't 'flow' it's current that flows. Voltages (strictly speaking potential differences) appear when current flows through resistances.
 
trevor lyndsey does a book (not bad) that covers the 2330 level 2 that goes through all the calculations ive just started level 3 and the book helped me alot.
 

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