Oscilloscope comes with no ground power cable? - Page 1
Forum section: electronics / beginners

author: xinsnake
author_rank: Newbie
timestamp: May 28, 2019, 08:50:03 pm
content: Hi everyone, I am a new forum member here, and I am fairly new to electronicsI bought a Hantek DSO4104B from AliExpress and the scope is great with everything working as expected.The question I have is that the scope comes with a power cable with no ground (i.e. only 2 pins on the plug for 240v AC). Is this normal and should I use a power cord with proper 3 pins? My understanding is that having only 2 pins on the power plug makes the scope floating which can be a safety risk, after watching Dave's video about how not to destroy your scope...Thanks!!

author: Roeland_R
author_rank: Regular Contributor
timestamp: May 28, 2019, 09:21:14 pm
content: When your wall outlet has ground springs your scope is grounded using the showed connector.

author: rstofer
author_rank: Super Contributor
timestamp: May 28, 2019, 09:29:11 pm
content: It looks like the ground pin is removable. I may not be seeing it right (old age) but it looks like there is a ground pin in the package.

author: wraper
author_rank: Unknown
timestamp: May 28, 2019, 09:30:55 pm
content: This plug has earth connection, actually 2 of those. You on the other side of the earth just don't understand it.

author: Benta
author_rank: Super Contributor
timestamp: May 28, 2019, 09:58:20 pm
content: Quote from: wraper on May 28, 2019, 09:30:55 pmYep. This type of plug is standard for 230 V equipment almost all over the world, aka "Schuko".https://en.wikipedia.org/wiki/SchukoIt has earth, both on the side clips as well as in the "hole".

author: techman-001
author_rank: Frequent Contributor
timestamp: May 28, 2019, 10:34:04 pm
content: Quote from: xinsnake on May 28, 2019, 08:50:03 pmThat's a USA power plug in your picture yet your ID shows youre in Australia ? the Australian plug is totally different. Did you not get a Australian IEC cable and three pin plug with the unit ?

author: xinsnake
author_rank: Newbie
timestamp: May 28, 2019, 10:45:38 pm
content: LOL Thanks for clarifying. I always thought the ground pin is like a pin...

author: xinsnake
author_rank: Newbie
timestamp: May 28, 2019, 10:47:16 pm
content: Quote from: techman-001 on May 28, 2019, 10:34:04 pmIt is a EU plug I guess and yes I am in Australia which means my power socket doesn't have the top and bottom connector for ground. I am now using an Australian cable to connect the scope.Thanks!

author: xinsnake
author_rank: Newbie
timestamp: May 28, 2019, 10:48:36 pm
content: Quote from: Benta on May 28, 2019, 09:58:20 pmThanks! I guess I need to use an Australian plug as my power socket won't have the "side clips" if I use a travel adapter for example. Thanks for clarifying!

author: soldar
author_rank: Super Contributor
timestamp: May 28, 2019, 11:17:45 pm
content: Like most plugs available today, Schuko is a bad compromise. The two round pins have good current capacity and that's about it. It is not polarized and I have marked all the outlets in my house with a felt marker and all the plugs to mark the hot side. The side earth clips I do not really trust to make good contact and can get bent out of shape if caught wrong when inserting the plug. Some countries have an earth pin which goes into the hole in the plug and that seems to me to be a more reliable earth.It is too bulky and depending on what plug and what outlet sometimes way too much force is required to pull it out. Which sometimes means you're pulling the socket out of the wall. The positive aspect of Schuko with respect to American plugs is there is now way a Schuko is falling out and disconnecting by accident.I realize all plugs and sockets are the product of compromises when they were designed but the Shuko plug should be replaced by something better.

author: SparkyFX
author_rank: Frequent Contributor
timestamp: May 29, 2019, 12:31:24 am
content: Thats a CEE 7/4, intended for most european countries and compatible to the sockets found there.You simply got the wrong cable in the box.I would have assumed that these do not fit into australian sockets, but anyway... ask the seller to send you the proper cable, the scope is better operated grounded, unless you really know what you are doing.

author: Brumby
author_rank: Unknown
timestamp: May 29, 2019, 12:38:49 am
content: Quote from: xinsnake on May 28, 2019, 10:48:36 pmTravel adapters are not the sort of thing you should plan on using for everyday. They are a convenience thing and are made for "travelling".If the item has a regular IEC socket and you're going to be using it in Australia, there's no excuse to not get a proper power lead. There are several members here who would toss you one or two for free if you were close enough.

author: Brumby
author_rank: Unknown
timestamp: May 29, 2019, 12:42:27 am
content: Quote from: SparkyFX on May 29, 2019, 12:31:24 amIndeed.If this was a product sold to the Australian market, then the seller should provide the correct mains lead.

author: KaneTW
author_rank: Frequent Contributor
timestamp: May 29, 2019, 01:17:40 am
content: Out of all sockets I was exposed to, I like Schuko the most. Maybe the French etc. 3-pin variant is a bit better due to polarization, but I don't know of any pluggable appliances that require correctly polarized voltages.

author: kcs
author_rank: Regular Contributor
timestamp: May 29, 2019, 01:43:30 am
content: Quote from: soldar on May 28, 2019, 11:17:45 pmWhy would an average home user need a polarized socket? What equipment used at home requires polarized connection?Quote from: soldar on May 28, 2019, 11:17:45 pmI have yet to face such a case when agood quality socketis being used. Actually, I have never heard this complaint before.Quote from: soldar on May 28, 2019, 11:17:45 pmCompared to what? I would say it is not bulky compared to British or Australian plugs.Quote from: soldar on May 28, 2019, 11:17:45 pmIf everything is properly done and good quality products are used, it is never the problem.

author: KaneTW
author_rank: Frequent Contributor
timestamp: May 29, 2019, 02:28:03 am
content: Agreed. I've never seen the earth clip get bent or the socket pulled out of the wall. British/Aus plugs are gigantic and American plugs are a walking safety hazard.

author: vk6zgo
author_rank: Super Contributor
timestamp: May 29, 2019, 05:15:07 am
content: British plugs are large, but Australian ones are not much different in size to a Schuko.Some manufacturers used to supply Schuko plugs packed up with their equipment, (because that's how the factory packaged them).The local branch just chucked in a separate box full of Oz standard IEC cables.I guess they thought we would just dispose of the EU ones, but we always needed IECs, so we cut off the existing plugs & wired Oz plugs on, getting extra cables just for the cost of a plug.That's why I know the relative sizes.What I like about Australian plugs is their simple construction, which still meets all the requirements.American 240v plugs are horrifically complex things.

author: Berni
author_rank: Super Contributor
timestamp: May 29, 2019, 05:40:05 am
content: I will admit that our EU plugs do have some downsides, but they are pretty good in comparison to others.Most use the ground in the sides, but there are a few weird plugs (I think Czech and France uses them) that have a pin sticking out of the wall socket that goes into that hole. Those weird "unicorn" wall sockets are actually the superior type.These have a better ground connection, can't get bent and are polarized for live and neutral while being the exact same size.The fact that EU sockets are difficult to unplug is mostly due to the significant contact force on the prongs and ground. This is a good thing because it makes sure there is a solid contact since all sockets are rated for 16A 230V continuous, providing 3kW from all standard sockets rather than requiring separate special high power sockets like in the US.And yes if a EU socket is exposed to a lot of rough handling the ground pin on the side gets caught upon plugging in and gets flattened against the bottom of the socket, making the pin non functional while the power prongs make contact. Tho since there are two ground contacts the other one still makes contact and keeps it safe.

author: Jeroen3
author_rank: Super Contributor
timestamp: May 29, 2019, 06:00:33 am
content: Is this topic unfolding into a flamewar whose mains sockets are best?All of the different sockets remind me of this:

author: Circlotron
author_rank: Super Contributor
timestamp: May 29, 2019, 07:26:01 am
content: Quote from: wraper on May 28, 2019, 09:30:55 pmGive us time!

author: Brumby
author_rank: Unknown
timestamp: May 29, 2019, 08:57:54 am
content: Quote from: kcs on May 29, 2019, 01:43:30 amQuote from: KaneTW on May 29, 2019, 02:28:03 amBritish plugs, yes - but Australian plugs? (channeling John McEnroe) ....You cannot be serious!Being over-engineered and containing a fuse, it is no wonder British plugs are the size they are - but Australian Plugs are nothing like those...Quote from: vk6zgo on May 29, 2019, 05:15:07 am

author: Electro Detective
author_rank: Super Contributor
timestamp: May 29, 2019, 09:59:36 am
content: Locally made Australian 240v plugs and sockets (and cables) were great up till the penny pinching corporats began cheapening them up via OneHungLow.Now we have on offer overpriced suss sockets with crappy switches, flimsy plastic coated halfassed plug prongs that bend if you look at them nasty etcThe newer 3 phase gear look like toys too, and unlikely they can handle a lot of plug in/out ab/use over time.I'd like to see if a OHL rebadge 32 amp combo can handle a real 32 amp loadwithout sizzling, sparks n smokeI do like the UK 'fuse in the plug' thing,although I don't know how or when a 13 amp fuse is going to protect an unfused soldering iron made by'blessed by electroangels'Murphy Free manufacturer 'W'

author: Gyro
author_rank: Super Contributor
timestamp: May 29, 2019, 11:02:27 am
content: QuoteThat's why we have other value fuses too. 3A, 5A, and 13A are standard, with 1A, 7A(?) harder to find. Of course even a 1A fuse won't protect the soldering iron, but at least it will protect the thin cheap cable.

author: mikerj
author_rank: Super Contributor
timestamp: May 29, 2019, 11:17:30 am
content: Quote from: Gyro on May 29, 2019, 11:02:27 amThough I would hate to guess how many plugs have the wrong value fuse in them (or a blown fuse wrapped in aluminium foil).

author: Brumby
author_rank: Unknown
timestamp: May 29, 2019, 11:45:52 am
content: Please - let's not go into the subject of fuse substitutes......

author: soldar
author_rank: Super Contributor
timestamp: May 29, 2019, 12:36:10 pm
content: Quote from: Berni on May 29, 2019, 05:40:05 amI agree with this. The "unicorn" pin provides better and more reliable earth contact. And polarization which is good. With regards to polarization Schuko is the exception and I believe pretty much all the rest of modern standards are polarized.The Schuko plug is very old and was probably the most advanced in its time but now has serious flaws. The earth clips were added later and are not really a good solution. A third, longer pin would have been better. You want the earth contact to make contact before the others.While Schuko is bulky it offers 16A compared to 10A of the common other systems (AUS, China, NEMA). 10 A at 230 V is generally enough for most applications but it is good to have the extra ampacity.It would be interesting to know if round or flat pins are better electrically (my guess is round is better) and which ones are cheaper to produce and more convenient to manufacture.

author: janoc
author_rank: Super Contributor
timestamp: May 29, 2019, 01:25:21 pm
content: Eh, don't complain about Schuko - you have likely never seen older Danish or French installations where non-recessed (!) outlets are common and many don't even have a ground connection at all (even the round ones capable of accepting a cable like shown by the OP).The German "non-unicorn" Schuko on German appliances is annoying because it is an incompatible exception in Europe (most other plugs/outlets mate together, maybe with the exception of Italy and Switzerland/Lichtenstein who use weird variants of the 2 pin plug with an extra ground pin), but I have never heard anyone complaining about the issues you have described.

author: soldar
author_rank: Super Contributor
timestamp: May 29, 2019, 03:04:04 pm
content: Well, I wouldn't say I am "complaining". Just commenting on the differences between systems. Schuko design is 100 years old and it is understandable that it is not perfect by today's standards. We still use many designs which are not the best but they have been grandfathered in. If we had to design a new plug system today from scratch we could do much better than Schuko.I think I am going to design and patent my own superior system

author: Zbig
author_rank: Frequent Contributor
timestamp: May 29, 2019, 03:20:57 pm
content: Quote from: Berni on May 29, 2019, 05:40:05 amDon't assume that the fact you're forced to stick the plug in the certain way makes them polarized. Sadly, that'soften not the case

author: janoc
author_rank: Super Contributor
timestamp: May 29, 2019, 04:17:32 pm
content: Quote from: soldar on May 29, 2019, 03:04:04 pmSure but that is a purely academic debate. Ain't happening, because the costs would be enormous.Even though if EU should work on harmonizing something, the crazy amount of different variously incompatible mains plugs, outlets and electrical standards that exists in Europe would be a good start. Not holding my breath for that one happening in my lifetime, though.

author: wraper
author_rank: Unknown
timestamp: May 29, 2019, 04:28:33 pm
content: Quote from: soldar on May 29, 2019, 03:04:04 pmWhen something like this happens, you then have both old and new standards, in result adding even more confusion.

author: wraper
author_rank: Unknown
timestamp: May 29, 2019, 04:35:33 pm
content: Quote from: Berni on May 29, 2019, 05:40:05 amSuperior my ass. Recently I was trying to put a plug into such socket. It wasn't going in (with proper orientation), so I pushed a bit harder. Guess what, earth pin was pushed inside the socket and shorted to line thus triggering circuit breaker.

author: Benta
author_rank: Super Contributor
timestamp: May 29, 2019, 05:59:02 pm
content: Quote from: wraper on May 29, 2019, 04:35:33 pmThat has nothing to do with CEE 7/7 as such, but with someone installing cheap, inferior receptacles. A different thing altogether.

author: wraper
author_rank: Unknown
timestamp: May 29, 2019, 06:14:05 pm
content: Quote from: Benta on May 29, 2019, 05:59:02 pmNope, it has direct relation. Sockets are made from relatively thin plastic compared to solid moulded plugs, especially extension cords. So solid prong sticking out of it asks for trouble. Particular extension cord was not cheap at all.

author: janoc
author_rank: Super Contributor
timestamp: May 29, 2019, 08:39:39 pm
content: That something is expensive has no bearing on quality. E.g. here in France you can buy plugs and outlets ranging from good quality brand names ones (usually Legrand and similar) to utter disasters that are unusable, break at the smallest provocation and are an electrocution/fire hazard in the worst case. And all bear the state certification logo! The price difference is often fairly minimal.The failed socket you had was poorly made and the pin was either not welded in properly or the weld has failed. Thickness of the outlet plastic has no bearing on it because the ground pin is always supported from behind.I am from a country that has these outlets with a grounding pin sticking out, here in France these are the rule as well and have never in my life (40 something years) encountered a socket where you could push the pin in while inserting the plug.If the plug isn't going in properly then either something is deformed or, much more common on recent sockets, the stupid protective shutters in the holes of the outlet don't want to open. I am routinely taking this BS out. If the shutters are in place it can literally take serious pounding and wiggling to insert a plug, even on good quality outlets. If that's the case, do yourself a favor, open the socket and take this nonsense out. You will thank me later. It is only a sliding piece of plastic and a spring.If someone is worried about kids, there are lockable plastic plugs that can be inserted into the outlets available, preventing a curious kid from messing with an outlet.See e.g. here:http://abc-electronique.com/annuaire/montages/cache/1457/muliprise2.jpgThis is a typical, bottom of the barrel, cheap piece of crap extension cord available here. See how is the ground pin welded/riveted to the busbar at the top? And that bar is supported from behind by the other half of the case. Those pins aren't going anywhere, even on this piece of junk.The photo also shows the protective shutters - the diagonal plastic things with the green covers under the live and neutral bus bars.Or this one (combo with a switch on the left):http://leslogesdeserrigny.fr/wp-content/uploads/2019/01/brancher-prise-electrique-avec-sch-ma-lectrique-pour-branchement-interrupteur-prise-idees-et-inter21313425394-avec-brancher-prise-electrique.jpgSee the metal earthing strip? That's what is holding the earth pin. The plastic has no role in it. If you have managed to break the pin off from that thick brass strip, that's not normal.

author: soldar
author_rank: Super Contributor
timestamp: May 29, 2019, 09:10:08 pm
content: Quote from: janoc on May 29, 2019, 08:39:39 pmI agree! I hate them with passion!The problem is many extension cords are built in such way you cannot open them without destroying them. Arghh!

author: Benta
author_rank: Super Contributor
timestamp: May 29, 2019, 09:32:02 pm
content: Quote from: wraper on May 29, 2019, 06:14:05 pmI've never experienced anything like this happen, but perhaps you have a local manufacturer using papier-mâché for the receptacles?

author: wraper
author_rank: Unknown
timestamp: May 29, 2019, 09:48:07 pm
content: Quote from: janoc on May 29, 2019, 08:39:39 pmSupported from behind by what? 0.5-0.8 mm copper or brass strip at best which holds to plastic by plastic melted through some holes in it.

author: Berni
author_rank: Super Contributor
timestamp: May 30, 2019, 06:03:17 am
content: I have only ever seen these french "unicorn" EU plugs when traveling to places, we use the classic german Schuko here. So i have no idea how reliable and resilient they are in practice, but the overall design looks better to me.Tho if its a plug pissing contest i do have to admit that the UK plugs are probably the best design, They only thing against them are the bulkiness and how painful it must be to step on one.At least for 3 phase outlets things are reasonably standardized in Europe with IEC 60309 .Tho over here you will still find the old yugoslavian 3 phase socket(Basically a wider Shukko with defined polarity and extra pins) everywhere in houses built more than 20 years ago.Quote from: janoc on May 29, 2019, 08:39:39 pmOh yes the child safe shutters are horrible on EU plugs. They keep jamming up and refusing to open, then as you punch the back of the plug to finally force it in that deforms them even more and so they will be even more reluctant to open in the future.

author: janoc
author_rank: Super Contributor
timestamp: May 30, 2019, 09:04:40 am
content: Quote from: wraper on May 29, 2019, 09:48:07 pmEver tried to push the pin through that metal or plastic? By a bare hand (not a hammer?). Seriously, have you ever opened one of the outlets you are criticizing? Also, I hope you do realize that there are many different models and different constructions. And here you are extrapolating - from a (crappy) sample of one that has likely been abused too (there is nothing to push the pin in with unless the plug isn't mating properly and/or the contacts in the grounding hole are deformed).If these outlets were so bad and so dangerous (ground pin getting loose and shorting out is certainly a fire/safety hazard!), they would have been forbidden from use decades ago. And I don't see that happening - they are in use in France, Czech republic, Slovakia, Hungary, Poland and elsewhere, with no problems.

author: wraper
author_rank: Unknown
timestamp: May 30, 2019, 11:13:39 am
content: Quote from: janoc on May 30, 2019, 09:04:40 amHave you read my original complain?QuoteI have the same question for you. I did.QuoteAs I've opened them and have seen a construction, I see it as significant concern.

author: soldar
author_rank: Super Contributor
timestamp: May 30, 2019, 01:08:10 pm
content: Quote from: Berni on May 30, 2019, 06:03:17 amThey can be used as a throwable weapon if you need to defend yourself from EU bureaucrats or other evil-doers!

author: Pluscrafter
author_rank: Regular Contributor
timestamp: May 30, 2019, 01:57:45 pm
content: And what about swiss plugs?Gesendet von meinem G8341 mit Tapatalk

author: janoc
author_rank: Super Contributor
timestamp: May 30, 2019, 03:05:08 pm
content: Quote from: wraper on May 30, 2019, 11:13:39 amYou mean this?Quote from: wraper on May 29, 2019, 04:35:33 pmBecause I can't find any other complaint.Quote from: wraper on May 29, 2019, 04:35:33 pmHow many do I need to open to show you that you have got a poorly made product and are making sweeping assumptions from a sample of one?Quote from: wraper on May 29, 2019, 04:35:33 pmReally? Heck, there are outlets like these where the "guts" are actually held in a piece of ceramic and no plastic at all! But you have obviously seen them all. Your country doesn't even use these outlets normally (assuming you are residing in Latvia), so I wonder where are you getting them from. Buy a proper Siemens or Legrand outlet and then criticize.

author: wraper
author_rank: Unknown
timestamp: May 30, 2019, 03:21:19 pm
content: Quote from: janoc on May 30, 2019, 03:05:08 pmYes, but according to you "a bit harder" = I used hammer. Supposedly you stood behind me and have watched how it happened.QuoteBroken was sample of one. But I've opened way more than one to see construction in general. With usual Schuko sockets something like this won't happen even if you use hammer.QuoteIf you read more carefully, I was talking mostly about extension cords. Though ceramic won't work well against hammer hit on the prong. BTW ceramic in sockets is rarity nowadays.

author: soldar
author_rank: Super Contributor
timestamp: May 30, 2019, 05:08:32 pm
content: Quote from: Pluscrafter on May 30, 2019, 01:57:45 pmThe cuckoo clock!They're like money in the bank.They don't lose more than five seconds per month.They were chosen in a referendum.The overture is William Tell.They feel like they're made of cheese (that superior comestible).The proper technical name is "Unus pro omnibus".You can't canton, acanton or decanton them.The "earth" connection is called "Alp".. . .Ok, OK, I'll see myself out now.