220V power  - Page 1
Forum section: electronics / beginners

author: orangepi
author_rank: Newbie
timestamp: April 08, 2018, 07:53:08 am
content: Power up 240V over .5mm diameter copper wire will burn your house. lol~ Even though it's a small experiment, it will burn your house and neighbors and all environment.

author: tszaboo
author_rank: Super Contributor
timestamp: April 08, 2018, 07:57:45 am
content: Not mathematical. The UTP cable and the connector is not rated for 220V. A CAT5 cable is only rated to 72V DC, 0.6A. The connector is not touch proof, and the clearance and creepage distances are violated. It is averybad idea.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 08, 2018, 08:17:49 am
content: Possible, yes. Sensible, no.There is no inherent efficiency difference between ac and dc.

author: tszaboo
author_rank: Super Contributor
timestamp: April 08, 2018, 08:31:01 am
content: Quote from: orangepi on April 08, 2018, 08:01:18 amSo, listen to them maybe?

author: fourtytwo42
author_rank: Super Contributor
timestamp: April 08, 2018, 08:34:01 am
content: Quote from: orangepi on April 08, 2018, 08:01:18 amMaybe that should be telling you something rather than blundering on against everybody's opinions. Use a roperly rated cable for the job together with properly rated connectors. I heard that in Australia licenced electricians are required for everything mains related, I thought that was over the top till I read your thread

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 08, 2018, 08:42:39 am
content: If your first post was clearer about what you were actually asking, you would get better answers.Look up the resistance per metre of the cable, and the max permissible voltage drop for your load,then apply Ohm's law.The usual solution is to use 24 or 48v, with a DC-DC converter.at the load.Or PoE if you also need data

author: BravoV
author_rank: Super Contributor
timestamp: April 08, 2018, 08:50:30 am
content: Quote from: orangepi on April 08, 2018, 07:53:08 amHow do you "know" that AC power has "far better" efficiency in voltage drop vs DC.Show the mathematically why ?Fyi, 220 VAC (RMS) "equal to" 220 VDC ... there you go, apply with the same formula you used above.

author: Twoflower
author_rank: Frequent Contributor
timestamp: April 08, 2018, 08:53:15 am
content: QuoteEr, no. Check for dielectric losses. Or why do you think in some places they take the detour to rectify andtransmit DCand going back to AC. For sure not just for fun.

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2018, 09:18:24 am
content: Quote from: orangepi on April 08, 2018, 09:03:01 amIt's NOT about mathematically proving ~80mA is possible over 24 AWG cable for ~20m, we all know it is.It's YOU not listening to highly experienced members of this forum !230VAC overUTP classcable is NOT SAFE and very unwise. Period !

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2018, 09:32:46 am
content: Quote from: orangepi on April 08, 2018, 09:29:32 amRead again and try to understand......if you can.Go ahead and try it, just be sure you don't electrocute anyone or burn the house down.Darwinian award candidate don't you think guys ?

author: Twoflower
author_rank: Frequent Contributor
timestamp: April 08, 2018, 09:36:05 am
content: I haven't said that the effects apply of your 20m cable running 50Hz. But your assumption AC is better for transport power is not correct.Transport power with higher voltages makes sense. Until you run into physical limits. Breakdown of the insulation within the cable, creeping distance and security reasons.The down side with AC is that the peak voltage is different with the effective voltage. So your 220V has actually about 311V peak voltage that your insulation has to handle. And do you know that in residential areas for example in Germany (EU?) the devices has to accept even surges up to 1kV on mains?Under specific conditions you can probably run higher currents and/or higher voltages over that cable without something happens. As there are security margins. But they are there for a reason. Especially bending cable will waken the voltage resiliency and increasing the thermal insulation of the cable in a cable channel/embedded in wall insulation will increase the temperature significantly.Violating specific rules put you, other people and your environment in danger and probably no insurance will cover that.

author: nali
author_rank: Frequent Contributor
timestamp: April 08, 2018, 09:42:24 am
content: Leaving the unsuitable choice of cable aside, I think he's just  asking whether to run 220VAC or 5VDC over the 65ft."AC" -> mains power"DC" -> 5V (or whatever the Pi uses now)"Transformer" -> SMPSU

author: Twoflower
author_rank: Frequent Contributor
timestamp: April 08, 2018, 10:14:50 am
content: You know current causes 'flashovers' its the voltage.I mentioned there are rules that 'limits' the usage. I also mentioned that you can run more current through a wire. In theory if you put a wire into a rim you can currents through that wire until the copper melts. Or better it can run currents until it is evaporated or build up copper oxide. Probably in theory you can build up a plasma out of your copper and run current through a plasma out of the atomic nucleolus and free electrons. I would assume the copper of your AWG24 will allow for several thousands kAmps.The voltage limit is a bit more complicated. Even in vacuum you can get breakdowns. So there's the distance the limit. Lookup for "breakdown field strength" for more information based on material.The manufacturer of the cable designed it that way that is guaranteed to maintain a safe operation under the given conditions. So in fact there is a big part of uncertainty they have to cope with.And by the way: If you think that everyone else is to stupid to understand your question I would think about that maybe the question is not understandable. And blaming people doesn't help. Be lucky that you get actually answers after the way you talk to them.I think I'm out and enjoy the nice weather here.

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2018, 10:29:06 am
content: Quote from: orangepi on April 08, 2018, 09:50:43 amOnly once is enough and it hasn't changed my POV.~15W (5Vx3A) is bugger all but 220V on a cable that's only designed and rated for LV is the problem.Why do you not understand that ?Pick a 24 AWGmainsrated cable and none of us will have any problem with it.

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2018, 10:42:15 am
content: Quote from: orangepi on April 08, 2018, 10:39:35 amMains rated UTP cable spec.

author: ovnr
author_rank: Frequent Contributor
timestamp: April 08, 2018, 10:46:25 am
content: Quote from: orangepi on April 08, 2018, 10:33:32 amDear orangepi: You obviously have insufficient knowledge of the subject at hand (which is, presumably, why you're asking here). A pile of experienced members are telling you this is an exceedingly bad idea. You'd do well to listen.As for the question of "WHYYY NO MAINS OVER ETHERNET": The insulation in the cable is insufficient to SAFELY run 220 volts. Yes, it'll WORK. Will it catch on fire a week later? Will it shock you, your pets, or make kittens spontaneously combust? Maybe.And "It might shock me" is never good enough, which is why we have standards for these sorts of things. I don't give a shit about your risk tolerance; there are other people in the world who will, at the very least, have to mop up after you fuck it up, not to mention the risk of hurting innocent bystanders. If you still think it's a good idea, please do go stick a fork in an outlet and lick it.(And as for "DURRR I WANT MATHEMATICAL PROOF OF WHY THIS IS BAD": Just... no. I'm sure you can see how towing a car with a bandaid isn't going to end well, or bungee jumping with a piece of string. Just leave it and go do something else, and leave the electronics to the grown-ups.)

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2018, 11:00:12 am
content: Quote from: orangepi on April 08, 2018, 10:47:16 amThen edit UTP out of the subject line.Do you not understand that's where we all have trouble with your idea ?If you need to safely supply mains power to a transformer and need data up/down in the same cable it's not a good idea with a single multi-pair cable. To safely do it you need 2 cables, one for mains (and suitably rated) and another for the data connectivity.

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2018, 11:14:00 am
content: Quote from: orangepi on April 08, 2018, 11:03:59 amClarity from you.Do you intend to use UTP cabling for 230VAC ?If so you're nuts !If not you should remove UTP from the thread subject line.Now take a step back and think about the answers you're seeking and then make sure your question can't be misinterpreted. From your reactions to replies I'm sure it has been.

author: tszaboo
author_rank: Super Contributor
timestamp: April 08, 2018, 11:20:43 am
content: Quote from: orangepi on April 08, 2018, 10:47:16 amI see one troll here, but it is not him.

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2018, 11:31:09 am
content: Quote from: orangepi on April 08, 2018, 11:25:14 amThread subject:220V power over 24 AWG UTP cable to the transformerfor 5V DC 3A for RaspberryPiWhat planet are you on ?Obviously not planet EEVblog.I hand it over to someone else to set this turkey straight.

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2018, 11:38:14 am
content: Quote from: orangepi on April 08, 2018, 11:35:47 amAh, OK so who's the troll with the click bait thread subject line ?

author: tautech
author_rank: Super Contributor
timestamp: April 08, 2018, 11:54:47 am
content: Ah, by deduction we might have some clues to what the OP really needs.From mains to ~20m away 5v @ 3A.Yep, PoE is the only viable way over UTP cabling.The OP can Google PoE, let's not do it all for him.

author: Monkeh
author_rank: Super Contributor
timestamp: April 08, 2018, 11:58:50 am
content: Go measure the thickness of the insulation on the cable and then look up the breakdown voltage of polyolefin insulation. Scale, apply standard insulation deratings, there's your mathematical answer.Once you've done that, go away.

author: Brumby
author_rank: Unknown
timestamp: April 08, 2018, 11:59:31 am
content: orangepi, you have only yourself to blame for the reaction you have garnered here.The original problem lies less in the responses - but more in how you phrased your question.It would seem to me that your question relates to the losses of 220V power over 65 feet of a 24 AWG conductor. That is a fair question.However, you muddied the waterscompletelyby adding a particulartypeof cable which is completely unsuitable for such considerations. That is your mistake - and you should take responsibility for that.But that's just the beginning. The fact that you are asking this simple question indicates you have a very limited understanding and that, coupled with the mentioning of a quite unsuitable cable, sets off the safety alarm bells of anybody and everybody who has the faintest inkling of the risk.THEN you get on your high horse and, rather than apologise for your poorly phrased question, you continue to defend it, claiming it was all very clear from the beginning. You have completely ignored any concerns from the members here AND you have taken them to task for being obtuse.Such an arrogance is not going to earn you any respect - and it is certainly going to put people off from even considering helping you. I mean, why should we stick our neck out when we can expect to be attacked if our interpretation of you questions are based on what yousaid- and not what you meant?If you want help, apologise for your actions, ask the question clearly (and, NO, you haven't done that yet) and act with some level of courtesy in dealing with the responses.As for me, I've spent enough of my time trying to help you by typing this up. I doubt it was time well spent - but I would like you to prove me wrong.

author: Monkeh
author_rank: Super Contributor
timestamp: April 08, 2018, 12:01:52 pm
content: Quote from: orangepi on April 08, 2018, 12:00:58 pmWhich they're not. Please proceed to the second part of my post.

author: Brumby
author_rank: Unknown
timestamp: April 08, 2018, 12:02:44 pm
content: Quote from: orangepi on April 08, 2018, 11:51:39 amHURRAH!This is the piece of clarification that wascompletely missingin the original question. Theimplicationwas there - but you had to work at it to see it.Implication is a bad means of communication , when it comes to EE.

author: Monkeh
author_rank: Super Contributor
timestamp: April 08, 2018, 12:22:34 pm
content: Quote from: orangepi on April 08, 2018, 12:21:00 pmThen perhaps you shouldn't have mentioned an obviously unsuitable cable type.Wait, you were looking to make trouble, not have a technical discussion..24AWG itself is fine electrically. Mechanically and in terms of cable construction it rarely, if ever, is applicable to mains voltage applications.Happy?

author: Brumby
author_rank: Unknown
timestamp: April 08, 2018, 12:23:56 pm
content: Quote from: orangepi on April 08, 2018, 12:21:00 pmYou are seriously deluded!READYOURTITLE.Not what youthinkit says - but theactual text you wrote. There's no sneakiness involved - just people taking notice of what you typed.

author: Monkeh
author_rank: Super Contributor
timestamp: April 08, 2018, 12:29:59 pm
content: ps. 65ft != 10m.

author: Brumby
author_rank: Unknown
timestamp: April 08, 2018, 12:30:35 pm
content: I'm sorry - but your interest in the technical discussion was not even in the race when compared to your interest in defending your poorly phrased question.Rather than apologise for the confusion, you blamed everybody else.

author: Gyro
author_rank: Super Contributor
timestamp: April 08, 2018, 12:36:13 pm
content: Quote from: blueskull on April 08, 2018, 11:54:12 amIt's RaspberryPi, surely.

author: Monkeh
author_rank: Super Contributor
timestamp: April 08, 2018, 12:38:57 pm
content: Quote from: orangepi on April 08, 2018, 12:34:47 pmAh, you assume I didn't see it immediately because I didn't immediately comment on it. It wasn't at all relevant - I just figured I'd take a small dig.Seriously, please go away.

author: ovnr
author_rank: Frequent Contributor
timestamp: April 08, 2018, 12:40:05 pm
content: I'd quite like him to stop calling posts "articles" too.

author: Brumby
author_rank: Unknown
timestamp: April 08, 2018, 12:43:50 pm
content: Quote from: orangepi on April 08, 2018, 12:32:35 pmThis:Quote from: blueskull on April 08, 2018, 12:34:05 pmYou come here with us not knowing what your background is and pose a question that explicitly mentions a type of cable that is completely unsuitable. This question is asked from a community of engineers and enthusiasts, many of whom have had direct experience in the safety aspects of EE - and others have a clear understanding of the risks.When we see such a first impression, the first thing we want to ensure is that you are suitably warned. Remember - we don't have the foggiest idea of what other advice you've been given, so don't blame us for repeating the same "crap". There's a reason it will get repeated. I wouldhopeyou understand what that reason is.As painful as it has been so far, we don't want to see you, your house or your friends and family suffer from a preventable tragedy.When you came here as you did - the initial impression you gave was exactly this.

author: Brumby
author_rank: Unknown
timestamp: April 08, 2018, 12:45:57 pm
content: Quote from: orangepi on April 08, 2018, 12:34:47 pmAdding more points on the Troll score sheet......

author: Brumby
author_rank: Unknown
timestamp: April 08, 2018, 12:49:18 pm
content: Quote from: orangepi on April 08, 2018, 12:45:06 pmA typical response from someone who has not won their battle - and is too arrogant to accept responsibility for their complicity.Don't let the door hit you in the rear on your way out.

author: Brumby
author_rank: Unknown
timestamp: April 08, 2018, 12:55:43 pm
content: !!! Bonus points !!!

author: Simon
author_rank: Unknown
timestamp: April 08, 2018, 01:25:10 pm
content: Perhaps we can all calm down and start with orangepi explaining what he actually doing. This thread seems to have little technical detail and the first post is confusing at best....

author: sokoloff
author_rank: Super Contributor
timestamp: April 08, 2018, 02:09:20 pm
content: Quote from: orangepi on April 08, 2018, 12:45:06 pmThose other sites seem to serve your purposes better; given that, I'd consider continuing to use them.

author: drussell
author_rank: Super Contributor
timestamp: April 08, 2018, 02:19:05 pm
content: To the OP, I first suggest looking up your local electrical code and investigating the appropriate regulations and specifications.Here in Canada, the minimum size of wire that may be permanently installed, run through walls, etc. forMAINSis 14 ga (AWG). This corresponds to the minimum conductor ampacity required for the minimum sized circuit, 15A (120v, 60 Hz, of course.) You are never allowed to use smaller wire, under any circumstances forMAINSinstallations. Low voltage, fine. You can use things like 18ga bell wire to wire your 24v doorbell, etc. There are separate regulations and requirements for these low-voltage circuits. In most parts of the world, these classes generally change at around 48 Vac or 60 Vdc, but it can vary by jurisdiction.An extension cord or appliance cord that is used to temporarily connect an item to a mains plug, never run through a wall or permanently installed, can be smaller and it is up to the manufacturer of the appliance or the user of the extension cord, etc. to ensure that the cable used is appropriately sized,however, there are still rules!Here in Canada, an extension cord or device cable on an appliance mayneverbe less than 18ga, even if the load is only a few watts. This allows enough ampacity to allow a breaker to blow if there is a short in the appliance before the wire bursts into flames.Interestingly, the only exception to the 18ga rule is for Christmas lights. "Tinsel Cord" as our code calls it, is allowed to be as small as 20ga, but modern regulations require a 3A fuse in the plug itself (typically a one-time, non-replaceable imbedded fuse) to help protect the tiny cord. Other than this, we typically don't have fuses in the device plug like they do in Britain.My main point is that you probably are never allowed to use 24ga wire of any insulation type to run mains. Underanycircumstances!It is a good idea for a reason and is minimum code for a reason. There is plenty of math behind these decisions and I suggest to the OP that he begin by doing the math as to how well a 24ga conductor will handle a fault condition at 220 volts and go from there.The reasons why you "don't do that" should begin to be self evident.

author: drussell
author_rank: Super Contributor
timestamp: April 08, 2018, 02:46:18 pm
content: Since the OP decided to change his original post and delete all the replies, I will just leave this original post here for posterity:Quote from: orangepi on April 08, 2018, 07:53:08 am