but there is no supply going to the switch there?
simplest question ever for a newbie
- Thread starter spark13
- Start date
Sponsored Links
B
breezer
look at the drawing and follow the wires
i am sir but can only see a supply going to the light not the switch
B
breezer
try harder, follow the wire
Sponsored Links
well it only says supply above the cable going direct to the light
balenza although i cant see ya on here i can smell ya in consideration to all the other people on here i urge you please BRUSH YOUR TEETH!
There are two things about electricity you need to understand.
1) It moves easily through metal, especially copper. Wires are made of copper. It does not move through plastic. That brown stuff around the wires is plastic. It does not move through air. It will move through you if you give it a chance but you really don't want to do that!
2) In order to move it must have somewhere to go. It will not move along a piece of wire if the end of that wire is surrounded by air. Think traffic jam. If the car at the front runs out of road, the ones behind it can't move either.
So far so good. Now for the tricky bit. Electricity is sitting in the live wire that comes into your house. It's come all the way from a substation through a live wire under the street and it would like to go back home along a neutral wire which is also under the street but it can only move through metal; not plastic, not air, just metal.
It can move along the brown wire in that cable marked "supply" until it reaches that thing in the middle. That thing is a terminal block and, although they aren't explicitly shown, there are four metal barrels in it which allow electricity to pass freely between wires on opposite sides. The spaces between the barrels are plastic so no electricity can pass from one barrel to another.
Let's follow the brown wire coming in on the left hand side of the top barrel. It can pass through the barrel to either of the two brown wires on the other side. It can go along either or both. Think traffic again. When a road branches, cars can take either route. One brown wire goes into another cable marked "supply to next". We aren't interested in that one. The other brown wire goes to the switch. That's how electricity gets to the switch.
What happens next depends upon what you do with the switch. What you have in there are two pieces of metal that are either touching if the switch is on or separated by air if the switch is off. Electricity does not move through air so if the switch is off there is nowhere for it to go. Let's switch on. The electricity can now move freely into the other wire in the switch. The one in the diagram is blue with a brown sleeve. Yours is brown. It doesn't matter. Electricity doesn't care what colour the plastic is!
Follow that blue wire and you'll come to the bottom barrel in the terminal block. Electricity can move freely through the metal barrel to the brown wire on the left hand side. It cannot pass through the plastic to the barrel above. The brown wire goes to the light bulb, inside of which is a very long piece of very thin wire. That's the filament. It doesn't look very long but if you use a good magnifying glass you'll see that it's wound into a spiral - and that spiral is wound into a bigger spiral. It's long!
So now we've reached the light, but there's more. No electricity will move anywhere unless there is somewhere for it to go. At the other end of the filament is the blue wire. Follow that back and you'll come to the barrel second from the top. There are two wires on the other side of that barrel. Which way, if any, will it go? There is only one way. The wire to the right may go lots of places but none of them are the way home. The only way home to the substation is to the left along the wire in the cable marked "supply" because that one goes back to your fuse box and from there out to the neutral wire in the street.
Can you see it now? With the switch closed there is a continuous line of metal - that's called a circuit - from the substation through the closed switch and the light bulb and back to the substation. It goes substation live side -> wire -> fuse -> wire -> barrel -> wire -> switch -> wire -> barrel -> wire -> filament -> wire -> barrel -> wire -> substation neutral side. You'll notice that a fuse has appeared in the list. That's not on the diagram but it will be there - in your fuse box.
Thus endeth the first lesson. Read it until it makes sense. It's not rocket science. Well maybe it was in Faraday's time but today's kids learn this stuff in junior school.
1) It moves easily through metal, especially copper. Wires are made of copper. It does not move through plastic. That brown stuff around the wires is plastic. It does not move through air. It will move through you if you give it a chance but you really don't want to do that!
2) In order to move it must have somewhere to go. It will not move along a piece of wire if the end of that wire is surrounded by air. Think traffic jam. If the car at the front runs out of road, the ones behind it can't move either.
So far so good. Now for the tricky bit. Electricity is sitting in the live wire that comes into your house. It's come all the way from a substation through a live wire under the street and it would like to go back home along a neutral wire which is also under the street but it can only move through metal; not plastic, not air, just metal.
It can move along the brown wire in that cable marked "supply" until it reaches that thing in the middle. That thing is a terminal block and, although they aren't explicitly shown, there are four metal barrels in it which allow electricity to pass freely between wires on opposite sides. The spaces between the barrels are plastic so no electricity can pass from one barrel to another.
Let's follow the brown wire coming in on the left hand side of the top barrel. It can pass through the barrel to either of the two brown wires on the other side. It can go along either or both. Think traffic again. When a road branches, cars can take either route. One brown wire goes into another cable marked "supply to next". We aren't interested in that one. The other brown wire goes to the switch. That's how electricity gets to the switch.
What happens next depends upon what you do with the switch. What you have in there are two pieces of metal that are either touching if the switch is on or separated by air if the switch is off. Electricity does not move through air so if the switch is off there is nowhere for it to go. Let's switch on. The electricity can now move freely into the other wire in the switch. The one in the diagram is blue with a brown sleeve. Yours is brown. It doesn't matter. Electricity doesn't care what colour the plastic is!
Follow that blue wire and you'll come to the bottom barrel in the terminal block. Electricity can move freely through the metal barrel to the brown wire on the left hand side. It cannot pass through the plastic to the barrel above. The brown wire goes to the light bulb, inside of which is a very long piece of very thin wire. That's the filament. It doesn't look very long but if you use a good magnifying glass you'll see that it's wound into a spiral - and that spiral is wound into a bigger spiral. It's long!
So now we've reached the light, but there's more. No electricity will move anywhere unless there is somewhere for it to go. At the other end of the filament is the blue wire. Follow that back and you'll come to the barrel second from the top. There are two wires on the other side of that barrel. Which way, if any, will it go? There is only one way. The wire to the right may go lots of places but none of them are the way home. The only way home to the substation is to the left along the wire in the cable marked "supply" because that one goes back to your fuse box and from there out to the neutral wire in the street.
Can you see it now? With the switch closed there is a continuous line of metal - that's called a circuit - from the substation through the closed switch and the light bulb and back to the substation. It goes substation live side -> wire -> fuse -> wire -> barrel -> wire -> switch -> wire -> barrel -> wire -> filament -> wire -> barrel -> wire -> substation neutral side. You'll notice that a fuse has appeared in the list. That's not on the diagram but it will be there - in your fuse box.
Thus endeth the first lesson. Read it until it makes sense. It's not rocket science. Well maybe it was in Faraday's time but today's kids learn this stuff in junior school.
You said it's in your friends place.I hope you are not intending doing any work for this friend as you are clearly out of your depth.If you are just wanting to know out of interest then keep reading, especially at Space Cat's post above, and hopefully, one day, it'll make sense.
But please DO NOT attempt any electrical work yourself for safeties sake.
But please DO NOT attempt any electrical work yourself for safeties sake.
Spark13,
In the diagram, below where it says, "supply" is a grey cable with 3 wires in it. The brown wire is the live feed to the lighting circuit in that room. The junction box doesn't show it, but opposite terminals are connected together, so you will see that the cable marked, "supply to next light" is connected to the supply cable. In fact they are both supply cables in their own right because they both carry live wires.
So, to work out the circuit, follow the connections of the brown wires and you will eventually arrive at the switch at terminal, "C", which is the Common terminal. The diagram shows the other cable as blue with a brown sleeve. This because cables mostly come with brown and blue (and earth) wires but we need to know which is the permanent live and which is the switched live. Switched live wires have the brown sleeve.
I hope you can understand the diagram now.
Your friend's house has been wired with 2 brown wires in the lighting cable. The wire that is connected to "C" is the permanent live supply. OK?
In the diagram, below where it says, "supply" is a grey cable with 3 wires in it. The brown wire is the live feed to the lighting circuit in that room. The junction box doesn't show it, but opposite terminals are connected together, so you will see that the cable marked, "supply to next light" is connected to the supply cable. In fact they are both supply cables in their own right because they both carry live wires.
So, to work out the circuit, follow the connections of the brown wires and you will eventually arrive at the switch at terminal, "C", which is the Common terminal. The diagram shows the other cable as blue with a brown sleeve. This because cables mostly come with brown and blue (and earth) wires but we need to know which is the permanent live and which is the switched live. Switched live wires have the brown sleeve.
I hope you can understand the diagram now.
Your friend's house has been wired with 2 brown wires in the lighting cable. The wire that is connected to "C" is the permanent live supply. OK?
B
breezer
Spark13, we would like to see you post again, i appreciate you are trying to understand how it works (for what ever reason)
I strongly recomend that you give up while you are ahead
I know in order to learn you have to ask, but you can not grasp the fundementals of how electricty works
remember this, electrictiy has no prejudices, it kills any one.
on a final note watch this
sit back and enjoy, then post back which bit is true
I strongly recomend that you give up while you are ahead
I know in order to learn you have to ask, but you can not grasp the fundementals of how electricty works
remember this, electrictiy has no prejudices, it kills any one.
on a final note watch this
sit back and enjoy, then post back which bit is true
ok just posted a message about scale diagrams then scrolled down to see ive apparently started a new topic on one way switching folks this was not me but just found out my annoying little **** of a brother i am first year student but been workin for over six months now i assure you i am aware of a one way! sorry for trouble caused rest assured an ass kickin has been dealt by the way he is 11!
- Joined
- 11 Jan 2004
- Messages
- 42,788
- Reaction score
- 2,647
- Country
Please...to make your posts easy to read, please use english!
as in SECURESPARK ya mean?
Might I suggest that, as a punishment, you make said little s**t write out the entire thread. Then you restore his internet access - and his playstation - and his iPod - well, you get the idea. Some of the information will stick and it might just save his life some day.
That reminds me. How did he find out about the two brown wires? You'd better confiscate his screwdriver too!
That reminds me. How did he find out about the two brown wires? You'd better confiscate his screwdriver too!
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
