Hey /diy/, electricity theory question time.
The diagram a) on my drawing is a parallel electrical connection, apparently the proper, safe way to connect few things (like 5 30watt cfl light bulbs in a bulb sockets in this case) to one plug (a 16 ampere 250 volts one in this case).
Now I was wondering OK but it's shit loads of additional cables and connection blocks... So... what if you would make a connection where you would put more wires into one block socket [like on diagram b)] and then eventually connect the blocks with just one cable if needed.
Would it be save or would you create a danger of frying the connection? (i.e. electrocution and/or a fire hazard)
Would you loose power (the bulb would shine less brightly)?
Is the parallel connection the safest and efficient way to do it?
If not can you think of something better than diagram b) that would still get you less messing around with cables and blocks?
It's troubling me because I don't know what knowledge do I need to have to know what you can or can't do with a grid so that it is safe and works the best.
So... Please share your thoughts, discuss rules, laws, ideas, tips and what nots on the subject, I'll be glad to hear anything that will make things more clear for me.
I'll complete the key to the drawing:
>The yellow cirlce is the bulb in a socket obviously.
>The triangle is a plug
>The "lego blocks" like squares are electrical connection block
>The blue line is live wire
>and the brown line is neutral wire
I also hope I'm in the right board to ask this.
And excuse my crude "masterpiece" drawing
Either way its fine as long as you don't overload the current rating of the terminal blocks and they are large enough to accommodate ask of the wires safely
There should be no exposed conductive parts and remember to crimp a ferrule over any multicore cable that you are clamping in a screw terminal
They're electrically the same.
b) would be preferred because there's less wire carrying the full load so smaller wire could be used after the initial run from the plug and the connections wouldn't carry as much.
Doesn't really matter though if you use heavy enough wire and solid connections.
Both cases require the wire from the plug to be able to power all the lights. on (b) the next sets of wires only carry about half. The downside is having to connect so many wires together
Protection methods are not an issue, I would even add some insulating tape on top of that. The thing you called
>overloading the current rating
is worrying me, but I would guess that the terminal block should be able to withstand around ~100watts, definitely you can connect single devices that suck in more than that.
If terminal blocks with big enough sockets are used then I guess it should be easier, I would put one wire above another, like a layer.
And if I messed something up we wouldn't understand each other and then you would be pissed that you don't get what I'm trying to figure out. The drawing gives me self-confidence that I am able to clearly describe everything (even if it's primitive), so if you want to be cool draw one that is a proper representation of my project and I'll love to take notes.
So, ok, I'm glad to know that this stuff would work, but the last question still applies. Can you think of a better way to connect those elements or is the b) diagram the best possible solution that you can get? (shortest cable route, least terminal blocks, safest, etc.).
Thanks for the constructive answers, I'm monitoring this thread every few hours, maybe there is more to learn.
Insulating tape is not protection it just makes things sticky.
If you need to add tape then you haven't done it properly.
The only time I would use tape would be for identifying eg marking a neutral wire as switched live and even then heat shrink is way sexier.
If you are using the terminal blocks I have in my head then they are designed to be relatively safe. As long as you strip the right length of insulation and don't have any exposed conductive parts then it should be relatively safe to handle, not that you should.
Typically the conductor size gives the maximum current while the thickness of the insulation gives you the voltage it will withstand before biting you.
You should avoid rating things like wire and connectors in watts as a high voltage low current wire can have the same power rating in watts as a low voltage high current wire. Using either in the wrong application could be fatal.
Work out the maximum current drawn by your setup first, then apply deratings as necessary (you will find pre computed tables for this online, if the cables are in free air then you don't have to worry, if you are bunching them together in a small space you should check this)
In reality 5 30w bulbs at 240v is fuck all, I don't know what your equivalent is but over here residential lighting circuits are 1mmsq cable protected by 6a breakers. That's about the smallest cable you get (you can buy smaller sizes in flex) and gives you a very healthy overhead for things like derating factors etc.
I'm guessing 16a plug puts you in the eu, unless you are using a ceeform/commando type.
Either way a breaker would be advisable, ideally rcd protection somewhere just be aware they don't discriminate, if you have an rcd in your fusebox/consumer unit it may trip even if you have a lower current one downstream. They don't work like fuses.
Every splice needs to be readily accessible for inspection and repairs.
If you're putting in can lights, if you buy the nice housings they have accessible splices from the hole the can is in if you drop the can.
10Ax110v = 1100w
But then again you need to focus on amperage when selecting wire size.
Another primary difference with B is that you can have up to 3 lines running through the same conduit rather than one depending on the path they take and if the paths are long that can add up costs very quickly.
So if you have more than what is shown in your diagrams you can quickly run out of conduit space and have to double up or get larger conduit and then again the cost of 6 small gauge lines can outweight one large gauge line.
EU you are very right and I already see some things that are new and interesting to me, so I'll elaborate.
There are of course different thicknesses of cables available here to choose from, but the most common one is 1,5mm^2 which can transfer up to 2000watts and withstand 450/750 volts (it's a standard all cables are in 0,3-0,7kV range). If that is a good rate of a cable.
Looking at things now, connecting 5 bulbs in one terminal block would keep us in a good watts range, but the volts at the connection, this is the very sore point.
So I guess now we have crystallized the main problem of idea with b) diagram which is, if the terminal block with multiple wires in it [like on diagram b)] wouldn't get overloaded?
On other hand you both mentioned a fuse. If you were to add a breaker then I understand you would do it in both causes, the a) and b) diagrams, not only in b) case?
And just share your opinion. If you were to connect 5 bulbs with one plug, would you do it like a), b) or choose something complete different?
Oh, and I'd also like to defend myself because I did talked about adding insulation tape, but on top of all other earlier mentioned protections, like an icing on the cake.
This stuff's interesting.
the voltage in the circuit is going to be 220v in the phase conductor and 0v in the neutral conductor.
both of your circuits are parallel circuits, the voltage will be the same everywhere in theory.
in both setups the bottom most terminal block will see 100% of the current but you don't need to worry about overloading current, 5x30w @230v is just over 0.6 amps, typically the smallest terminal blocks you can buy from a diy shop is 5/6 amps, the 1.5mm cable will easily do 5/6 amps too.
the layout depends on how it is laid out physically, whatever way costs less as long as you can fit all of the wires in the terminal block.
i really wouldn't bother with tape but do use some kind of strain relief, you don't want to pull a live wire out and have it dangling around.
I made another drawing of what I am thinking right now.
At the connection on the terminal block does the volts stack up?
is there a some explanation to your drawings looking like they were made by a retarded child? compare yours, for example, to one i made yesterday.
You could use a light switch plugged into the first outlet to switch the other two outlets.
Y'know, if you didn't give a flying fuck about electrical codes, standards, not creating deathtraps for unsuspecting users...
With this level of knowledge/misconceptions, you really SHOULDN'T be playing with mains voltage. In a parallel connection (i.e. the one you have drawn), all branches see the same voltage and the current gets added up.
And I repeat, you shouldn't be playing with live mains at this level of knowledge. You could, you know, get yourself killed very easily.
Current kills, not voltage but yeah, thread looking a but primitive. All OP needs to understand is ohms law, maybe kirchhoff's voltage and current laws. I think so long as you can use a multimeter to check to make sure whatever you are working on is dead, most of any potential fireworks will happen when you flip the breakers back on, worst case scenario is using undersized conductors which can heat up and melt, add resistance to the circuits.
OP could also fuck up fault protection (or not install any at all), which won't result in fireworks in and of itself, but is very deadly nonetheless. Even three-conductor mains installation behind a RCD is prone to errors like that (and it's suprisingly easy to wire improperly).
But knowing how to use a multimeter and understanding Ohm's and Kirchhoff's is a good foundation (which OP clearly does not have, hence my word of warning). Mains can and does kill, simple as.
>Current kills, not voltage
At the risk of having this thread again, P=V^2/(R+r), and for humans, R is sufficiently large that even if r were zero, V is what decides whether P is lethal, tickly, or imperceptible.
I actually really like that you did it yourself. It shows that you have thought behind your idea as opposed to mindlessly following some standardized thing. You could probably learn a thing or two from the standardized method though.
- think you'll find, besides the half-measure muricans and a few other oddities, 230v is the actual standard, with some 220/240v thrown in for a laugh. The 250v thing always puzzles me, tho..
>"In 2000, Australia converted to 230 V as the nominal standard.."
- your meters upside-down, you shitposting wallaby.
->more explanatory link
Like all good standards, 230v has a lot of flexibility in actual usage - you dont need +10% tolerances in electrical power generation either, it was just so the countries who were originally 240v could claim to be in compliance with the new standard, without actually changing shit.
>"In the UK and Australia the nominal supply voltage is 230 V +10%/−6% to accommodate the fact that most supplies are in fact still 240 V.."
..and bits are still actually 250v (because 'legacy' = fuckhuge trafos be expensive)
Hi, OP here. I guess we can say I have a major update and some information to share and confirm.
Today in the morning while eating breakfast I was still thinking about diagram b) so I decided F it and went to the store bought five bulb sockets, some cable, terminal blocks and I set up to do some research.
Now on the drawing (another one for you to criticize) you have the final outcome I was forced to agree to. And what can I say?
The space in the terminal block hole is a MAJOR problem (as >>925466 anon said).
I though I chose blocks with pretty large holes, but in the end I could put only 2 wires into one.
Now putting 3 was possible, but the wires were really, really squeezed, so for safety sake I decided to chill and add another block.
What's a good information is that the guy at the shop told me that it is actually kinda common to put more than one wire (that draw power like bulbs) into one terminal block, as long as you know what you do and won't put large amperage through.
So yeah, it works, but I wasn't able to really check the durability of the blocks because as I said the space in the terminal block holes do not allow it (which is pretty inconvenient to be honest).
Now my lesson from this experience is that if you wanted to make some improvised linking of few devices and a plug, that would not go into a wall and you could keep an eye on, the best way to go would be to use a twist connection (i.e. strip the isolation from the cables to the wire, put the wires of all the cable you need together [just remember to not excess the resistances of the cable watts, amps, volts], twist them with pliers, [eventually solder this shit], secure with some kind of a collar, make sure that the cable sits tight and doesn't move and voilà).
So yeah, that adventure was ok.
Damn, if I was able to stimulate your imagination so much then maybe I should become a painter.
Maybe I'll add some pics later
in EU its not 220+-10% its 230 +10% -6%, if you want to get pedantic then do it properly.
most of europe started at 220 and increased to 230ish to harmonise. uk started at 240 and didn't bother changing fuck all.
in reality mains is all over the shop depending on your country and where you live in that country.
mains at my cutout is a reliable and constant 249.9v and thats not even in a part of the uk where 250v used to be the standard, which it did in many places.
your voltage being higher than standard is likely due to you being close to a substation transformer, the voltage is high so that houses at the end of the feed can get a decent voltage too.
what kind of terminal blocks did you get that you can only fit 2 1.5mmsq wires into?
even a 5a one you should be able to get 2 wires in each side.
a chunky 50A one could fit 5 or 6 no problem.
>the best way to go would be to use a twist connection
Come on OP, now you're just trolling. The proper way is to use something like a WAGO terminal push-wire connector (pic related).
You would also want to connect L to the bottom contact point and N to the thread socket so as not to electrocute yourself when changing bulbs.
The kind from your pic-rel. Read once more, I said that I was able to put 3 in, but the wires were really squeezed in, so I decided to not take a risk.
About the WAGO thing, well yeah that sounds nice, and even less work.
About the socket thing, I'm not sure if I follow, but I guess socket standards and shit.
I'm adding pic #1 from my little lab (it's the upper 3 connected sockets and a plug from my drawing).
And I think you can even see looking at it that even a 2 cable connection is kinda tight, so now imagine if you added a 3rd one.
inb4 what's the green/yellow changing thingy.
it's the earth, I'm not using it so I just isolated it so it's not exposed.
>Now my lesson from this experience is that if you wanted to make some improvised linking of few devices and a plug, that would not go into a wall and you could keep an eye on, the best way to go would be to use a twist connection
Why wouldn't you just use a power strip?
And here's pic #2 and it's obviously the lower two sockets connected and a link cable.
As I said it was interesting to play around with.
Now I'm thinking damn I have 5 bulb sockets connected. What will I do with it, lol?
Well maybe one day I will need to illuminate something.
OR maybe I could build some custom made lamp out of it, shit that would be pretty rad.
Like I could add 3 switches and make it different ways aimed lights. I have 2+1+2 connections, so I could make the 1 go UP and the 2+2 go DOWN and to the SIDES or alternately LEFT/RIGHT + RIGHT/LEFT.
Hmm, I could think about a cool frame as well.
Yeah, I'm into it.
And yeah, well sad for me information is that I wanted to also post a pic with working bulbs, but the photo comes out all bright and you can't see shit, I can't figure it out with the filters for the life of me.
those are not cable but flex
i warned you about this earlier, you shouldn't be putting stranded wire into a screw down terminal like this, the fine wires break under the stress, they should be ferruled.
if you get wago connectors you should be ok, they seem to be fine with any kind of wire.
these terminal blocks look really small, you can get bigger ones.
>you shouldn't be putting stranded wire into a screw down terminal like this
If you have to use screw terminals you have to tin your wire ends before using them in a terminal block.
That looks deadly as fuck, OP. You realize there's live mains on the little screw heads? And the point I tried to make with wiring up the sockets - if you wire live to the thread socket, you get a very high chance of actually touching it when changing bulbs. All it takes is touching any metal part of the bulb thread. That's why you really should wire live to the bottom "contact pin". But, seeing your "creation", I'd say proper socket wiring is the least of your concerns.
Next time, use one of pic related for your braided flex cables. The ones you are using are for solid core cable.
And you should of course still crimp ferrules on the ends, or at the very least tin the strands together. And for god's sake cover the live parts so noone can touch them.
Next time, do what >>926007 said. Get a 5-socket power board and attach the plugs properly on your cables. Would be much safer, and actually very close to the way it was intended to be.
I understand that if the stranded wire breaks under pressure it can cause some sparks to appear, yes?
As I said I already tested this thing with all bulbs in and there was no sparking, only the bulbs got a little bit hot.
Also about ferrule I understand that you talk about it out of safety concern, but please understand that this thing is temporary, I am not intending to put it to house use and it just lies on the plastic mat in my little lab shining brightly.
STILL I am thankful for you worrying and for the words of warning, I do take them to my heart and if I'll decide to make something else, more permanent with this stuff (like maybe the lamp I mentioned earlier) I will make sure to secure it all properly.
I don't know how do you know that the sockets are wired wrong. I bought them already WITH the cable connected to them, so the only possible problem would be if I connected something wrong in the terminal block. It's good knowledge though and I will remember it, so thanks.
And about the live mains on the screws. Well if the screw is like half way in the plastic, because it's screwed in to hold the wire, then doesn't it mean you would have to actually squeeze your finger in so the skin make contact with the metal head?
I see that last few posts was a lot of panic. Guys relax, I'm not gonna put my dick into the socket.
The sockets may be wired properly, but it takes only one mistake on the other end to flip the connections. And with no switch in the way to disconnect both cables (and hardwired connection with no plug to take out), it's easy to see where this could go badly.
There is a plug, look at the drawing and then at the description of picture #1
a flip on the other end, again look at the picture and say that there is something wrong with the wiring
>could go badly
you are just looking for a hole in the whole aren't you?
Also I remind you that trolling is reserved for /b/
if you are just playing around on the bench then no problem but please be careful
yes it is hard to get a shock from the terminal block that is how they are designed
electrical current causes wires/connections to heat up due to resistance.
the heating makes the terminals and wire expand slightly. no electricity makes them contract.
the flex is made of many very thin wires under pressure from the screw, wires at the edge can work loose after many heating/cooling cycles. once free they are very thin and can easily break off, as an individual wire breaks the current carrying capacity is reduced and the heat at the terminal increases, more wires come loose and the problem gets worse and worse until the wire breaks cleanly or it gets so hot a fire starts.
loose wires can also cause shorts and things.
but on the bench having an experiment its no problem. just be safe, make sure the soket is out of the wall and nobody else can plug it in when you are working on it.
do not throw away a plug with wire attached, babies and children have died playing with these things
Posts like that one is why I started this discussion here, raw knowledge expanded with explanation I respect that, and I respect you for sharing, thanks.
Now from what you have said about heat and wires, one could deduce that it would be actually less damaging for the circuit to leave the power on for lets say 12 hours than to switch it on and off every 30 minutes in the same time. If that is correct, then it's very interesting, because if I was to use logic I would definitely point at the non-stop 12 hours run to be worse for the wires.
Second conclusion is pretty ironic, because you said that wires could get loose after cycles, so wouldn't it mean that if they are clutched together like in those double or even triple connections that I am researching all the time in this tread isn't it actually better for the connections as they sit tighter in the block holes? Would seem like it.
And final though right now is that amperage appears ones again in the discussion and proves to be the most important thing (because of the heating of the wires), so we made a full circle on the subject. This is also kinda interesting because it proves that everything follow and result out of something, so cause-effect relation applies as a hard argument and explanation.
See you tomorrow guys.
I'm not trolling. Just stay safe and do not electrocute yourself. For a temporary bench project it is almost fine, but please tear it down once you are done experimenting, especially if someone else has access to the area.
And finally I'd recommend inviting an electrician friend next time, someone who would help you and share knowledge.
>There should be no exposed conductive parts and remember to crimp a ferrule over any multicore cable that you are clamping in a screw terminal
Shit, this is actually kinda clever.
Until I realise you might end up trying to pull 300w through a 10w bulb.
Actually, scratch that, this could end up being pretty fun.
>Current kills, not voltage
You know very little. But just enough that it kinda makes sense to you.
This is dangerous, other anon is being kind but I have a genuine fear for you safety so I'll tell you to stay the fuck away form this stuff.
Still, fucking stop this OP, you're a moron.
>You realize there's live mains on the little screw heads?
You realise there's live mains inside every wallsocket in your house?
Quick, run and get that breaker unless you want to risk the lives of morons who seek out live electrical equipment and poke it with paperclips!
Terminal block is perfectly safe. There's an insulated shaft around each screw to stop you touching it with anything but a screwdriver. You're meant to use it inside a case, just like you would wirenuts.
UK light sockets are predominantly BNC, which doesn't have this problem: the connector is floating (or ideally grounded), and both terminals are at the bottom of it, and can go either way round. The bit of the bulb you can touch isn't a terminal, so it can never be driven to mains potential.
Hello again, OP here, I see that throughout the night nobody answered if it's less damaging to the circuit when the current is flowing through constantly, then when it is switched on and off in time periods.
As well as nobody confirmed the though that if wires are squeezed together in one block it makes them sit tighter even if flex damage taken in consideration.
That's kinda a shame, but hey another day!
>And finally I'd recommend inviting an electrician friend next time, someone who would help you and share knowledge.
Well, if I had someone like that, then I guess I wouldn't be sitting here and got my knowledge filled through a nice face to face conversation, right?
I'm a moron because I am trying to learn about something that is not my field of expertise, great logic.
I lack knowledge, that I will agree with and DUH that's why I am here asking questions and gathering both theoretical and practical information.
Well if it was like some kind of an oldschool bulb then I idk (and those oldschool bulbs were like 100w+), but with modern bulbs?
A standard CFL has things called a starter and a stabilizer and I guess they are there for a reason, not just because it's cool to add them.
Probably the reason nobody answered your question is that nobody really knows much about this kind of failure, it is well known that screw terminals, especially those dealing with high current like inside your consumer unit or fuse box should be done up properly, manufacturers usually now give torque figures to help. Not putting flex into a terminal block is something that I haven't come across in any electrical code but every electrician seems to had heard of it. Sometimes the response is that its ok as long as you have a piece of solid wire under the screw, the aim is to avoid the screw separating the wires of the flex and pushing them around as you tighten down
I do lighting installs professionally, and for stuff like this you really cannot go wrong using klik like sockets, plugs and distribution panels.
The current is not being held constant.
>Figure out the dependent term and use the correct equation.
Which is exactly what he told you to think about, and you stupidly went in and spouted the same tripe all over again.
Looking at what you said, it would mean that I'm exploring a blank spot on the map and became a sefl-proclaimed amateur scientist with my little research. World behold my heritage on electricity, lol.
But giggles aside, I could actually check this and confirm something new.
Now I'm thinking about putting a breaker on this creature, just like some of you guys mentioned, guess it would make everybody a little bit calmer, I might also be safer that way. The thing to be honest is that I forgot about it, when I got back home from the shop and took out all the things from the plastic bag right then I realized I didn't get the breakers.
Now wondering about those, can a breaker be used as an everyday light switch?
I'm thinking about that self-made lamp I mentioned earlier, I could make it look super industrial with low amp breakers instead of switches between the plug and the individual terminal blocks, the thing is again I don't know if it would be ok to do.
For my modest lab and a side study this stuff is bigger than cupboards in my kitchen.
But just for science I'll look it up, thanks for sharing.
I just use a candelabra adapter for an e27 socket. Way easier than what you're talking about.
Keep us updated if you get your work published.
There is nothing to stop you using a circuit breaker as a light switch except for the cost and time/effort involved.
Generally breakers are only meant to be operated occasionally so it might break long before a normal light switch would
OP, if your looking to piss about and learn take a look into rails and busbars, pic related, although strickly speaking they should be installed into an appropriate enclosure with strain relief.