Red is Negative, Black is Positive in China? - Page 1
Forum section: electronics / testgear

author: SNGLinks
author_rank: Regular Contributor
timestamp: April 09, 2015, 09:35:39 am
content: I have just received a volt/amp panel meter from China.Attached is the wiring diagram.I assume Anode is +ve and Cathode is -ve.I queried it and got the wiring diagram, as shown, sent to me.WTF?

author: amyk
author_rank: Super Contributor
timestamp: April 09, 2015, 10:01:40 am
content: No, anode is negative and red is still positive. They just drew the diagram rather confusingly.Compare:http://en.wiktionary.org/wiki/%E8%B4%9Fhttp://en.wiktionary.org/wiki/%E6%AD%A3

author: SNGLinks
author_rank: Regular Contributor
timestamp: April 09, 2015, 10:42:26 am
content: Thanks! Very confusing

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: April 09, 2015, 11:51:37 am
content: They used to have traffic lights that were red for go and green for stop. The last set I saw in 2 years of working there was outside Kunming and they were blue for stop but had been rewired to the international norm in the late 80s, although the red light was still at the bottom.Knock off NiCad and Nimh cells often have the printed sleeves assembled 'upside down'.I often saw trucks with two red lights at the front and two white lights at the rear - we then refused to be driven at night.BT

author: TimFox
author_rank: Super Contributor
timestamp: April 09, 2015, 12:53:55 pm
content: I have seen old (not up to current IEC specs) wiring in Europe where red was "ground" or "protective earth", instead of the present green/yellow, or green in US.

author: sync
author_rank: Frequent Contributor
timestamp: April 09, 2015, 03:57:07 pm
content: Quote from: TimFox on April 09, 2015, 12:53:55 pmYes, in Germany red was used for protective earth (1 phase cables) AND for L2 in a 3-phase system.

author: TimFox
author_rank: Super Contributor
timestamp: April 09, 2015, 05:50:16 pm
content: I have often wondered about the logic behind color-code choices, but using the same color for L2 and PE seems dangerous.The US standard for "line" in a single-phase system is black, with white for neutral. An electrician told that was because "black means death", which is presumably the mnemonic they taught him as an apprentice. As I understand it, the normal US code reserves white for neutral, green for ground/PE, and allows the other colors (including black) for "hot" wires (including switched).

author: sync
author_rank: Frequent Contributor
timestamp: April 09, 2015, 06:12:55 pm
content: I searched a bit and found that red was also used for switched line voltage. It's not only dangerous. It's completely insane.

author: electr_peter
author_rank: Unknown
timestamp: April 09, 2015, 06:46:00 pm
content: Regarding original post, DC wire colours may be misleading in situations where current is measured (because of multiplication of wires). Correct action would be to get a proper manual and/or double or triple check everything with a DMM before powering it up.

author: SeanB
author_rank: Super Contributor
timestamp: April 09, 2015, 07:03:10 pm
content: A small list in easy to understand form.https://en.wikipedia.org/wiki/Electrical_wiring#Colour_code

author: AG6QR
author_rank: Frequent Contributor
timestamp: April 09, 2015, 07:04:54 pm
content: Quote from: TimFox on April 09, 2015, 05:50:16 pmThis gets especially nasty when standards are mixed. As you point out, in regular household electric wiring, black is live, white is neutral, and green is ground. But for DC automotive use, a typical code is that black is negative/chassis, and red is positive.RVs or camper trailers are a hybrid of a vehicle and a house. They typically have AC and DC wiring. The AC is usually like house wiring, black live and white neutral. The DC is sometimes like automotive, red + and black -, but often it's also black/white, where black is +12V and white is negative ground, connected to the chassis.When I see a black wire in an RV, I never know whether it is connected to +12VDC, 120VAC, or chassis ground. Gotta test everything.

author: SeanB
author_rank: Super Contributor
timestamp: April 09, 2015, 07:21:42 pm
content: Work on aircraft, where every wire is white. Can be ground, 28VDC, 115VAC 400Hz, 2kVDC ( nasty to find on the connector, as they are rated for it) or anything in between. Only thing you can be reasonably sure of is the 00SWG wiring will be either ground or 28VDC.

author: Rick Law
author_rank: Super Contributor
timestamp: April 10, 2015, 01:31:34 am
content: Quote from: BurningTantalum on April 09, 2015, 11:51:37 amThat was not something "they used to do". That were changed by the Red Guards during the Cultural Revolution in the 1960's. As you would expect, in the view of the Red Guards, Red should mean means go.

author: daybyter
author_rank: Frequent Contributor
timestamp: April 10, 2015, 02:24:30 am
content: When I had to replace the battery of my ti 57 calculator, I had to learn, that red is also negative in Texas... :-)

author: timofonic
author_rank: Frequent Contributor
timestamp: April 10, 2015, 08:31:15 am
content: Quote from: daybyter on April 10, 2015, 02:24:30 amIn Texas and Arizona, red is negative! Or was black too?

author: mrf245
author_rank: Regular Contributor
timestamp: April 10, 2015, 08:54:40 am
content: Of course,RED is positive and BLACK is negivite in your picture(according to Chinese text)

author: elgonzo
author_rank: Unknown
timestamp: April 10, 2015, 08:58:40 am
content: Quote from: Circuiteromalaguito on April 10, 2015, 08:31:15 amNonsense! Red is the color of the GOP, thus red is very, very positive in Texas and Arizona.

author: babysitter
author_rank: Frequent Contributor
timestamp: April 10, 2015, 10:03:29 am
content: Black is red and positive is negative, of course.(Come on you had enough time to pull out this old joke)

author: Rick Law
author_rank: Super Contributor
timestamp: April 11, 2015, 12:54:22 am
content: Quote from: daybyter on April 10, 2015, 02:24:30 amAnd in accounting departments anywhere in the USA. Red=negative."Seeing Red"=="Big Yikes"Why is 12Volt so timid? Because it is always Yellow...

author: Paul Moir
author_rank: Frequent Contributor
timestamp: April 11, 2015, 03:59:02 am
content: Quote from: TimFox on April 09, 2015, 05:50:16 pmAnd of course, there's the exceptions. For example a common switch leg. This is where you wire power to for example a light fixture's junction box, then drop a 2-wire to a switch to turn it on and off. Since the 2-wire is white & black, what's an electrician to do?The code answer is to connect the switch's white to hot in the fixture's junction box, and connect the black wire to the fixture. The rational is if the fixture gets changed, the (presumably homeowner) is confronted with a white and black wire to attach to his new fixture, so there is no possibility for confusion. If the black switch leg wire was made the permanently hot one, the homeowner would see two white wires going to the fixture and so he would be liable to wire the fixture backwards.The mnemonic that stuck with me was "Down on the white, back on the black."

author: Chipmunk
author_rank: Contributor
timestamp: April 11, 2015, 04:13:52 am
content: Here in the UK it's pretty much the exact opposite, on a switch drop, the brown wire will be Live, as normal, and the blue will be the switched live to the fixture (sleeved in brown at each end if the electrician's following the rules). I tend to tape them brown AND sleeve, in case the sleeving falls off

author: Rick Law
author_rank: Super Contributor
timestamp: April 11, 2015, 06:21:05 am
content: Oh boy, this is a bigger mess than I thought.I fixed my heating system motor last year. Brown was something I already forgot, Blue is the the slow fan... at least the research I did then led me to think it was some kind of standard.Can color blind electrician even do the job? What if the same blower fan is taken to Canada? Would it kill someone when they hook it up according to their standard color scheme.I wonder if there is a high rate of accidents with electricians who happens to be recent immigrants to a particular country.

author: TimFox
author_rank: Super Contributor
timestamp: April 11, 2015, 02:02:47 pm
content: Quote from: Paul Moir on April 11, 2015, 03:59:02 amDoes the code allow adding colored electrical tape to the ends of the white wire in your example? I am familiar with blue and red tape used on three phase circuits, where the only wire available was black.

author: Fungus
author_rank: Super Contributor
timestamp: April 11, 2015, 03:04:02 pm
content: The people who decided the new "standard" also managed to forget about color-blind people:http://www.brighthubengineering.com/commercial-electrical-applications/107563-color-blindness-rules-for-electricians-and-electrical-engineers/The best colors would be black/white/stripey. The stripey wire would have to be higher contrast than yellow/green (which doesn't look stripey at all to people who can't see green).

author: KeepItSimpleStupid
author_rank: Regular Contributor
timestamp: April 12, 2015, 12:51:27 am
content: I learned early not to trust colors. In the thermocouple world red is negative.All white or all black wires were in a commercial instrument. Turned out they had numbers printed on them. Motors might too.The IEC colors blue/brown and green with white, I haven't found a way to remember yet.

author: videobruce
author_rank: Frequent Contributor
timestamp: April 12, 2015, 07:13:09 am
content: Quote from: SeanB on April 09, 2015, 07:04:54 pm.Notice, China is not included.

author: coppice
author_rank: Super Contributor
timestamp: April 12, 2015, 07:43:04 am
content: Quote from: videobruce on April 12, 2015, 07:13:09 amNotice, Japan is not included. What's your point?

author: SeanB
author_rank: Super Contributor
timestamp: April 12, 2015, 07:44:26 am
content: At least one Chinese manufacturer uses wiring of green, red and yellow. Green is common, red is live and yellow is neutral. As it in any case came with a Australian standard plug attached, I simply opened it, put a proper cable along with a proper cable gland ( as opposed to the original of a hole drilled through the metal with the cable through it with a knot inside) to comply with local colour specifications, and with a South African/Indian standard plugtop as well. Ground went to a proper nut, nylock bolt and washer with a lug as well, not the original bare wire wrapped loosely around a random screw thread inside.I did reuse the plug though, as Stuart had some Australian Yamaha gensets and was looking for a cheap source of the plugs, and I had also gotten some HP power leads with the Australian pattern as well so put them all together for him.

author: coppice
author_rank: Super Contributor
timestamp: April 12, 2015, 07:53:53 am
content: Quote from: SeanB on April 12, 2015, 07:44:26 am\The Australian standard plug and the Chinese standard plug are identical.

author: videobruce
author_rank: Frequent Contributor
timestamp: April 12, 2015, 07:55:08 am
content: Quote.The "point" is, China,notJapan is in the threads subject.

author: Zero999
author_rank: Super Contributor
timestamp: April 12, 2015, 02:01:33 pm
content: In the EU, the colour code for both AC and DC wiring is similar and the colour red is not part of this standard.ACL1 = BrownL2 = BlackL3 = GrayNeutral = BlueDCBlue is always the conductor which is at earth potential or is the centre tap on bipolar systems, so if it's negative earth it's -, if it's positive earth it's + and if it's bipolar, it's 0V.Brown = + on negative earthed, unearthed or bipolar power supplyGrey = - on positive earthed, unearthed or bipolar power supply.So if it's a battery powered installation and it's negative earthed you have:- = Blue+ = BrownBut if it's positive earthed you have:+ = Blue- = GrayI suppose it's easier to say:Gray = -VBlue = 0VBrown = +VThat's less confusing.Green & yellow is always protective earth, irrespective of whether it's and AC or DC system.The colours red and black, for DC systems have no official meaning, as far as the European wiring code is concerned.

author: Rick Law
author_rank: Super Contributor
timestamp: April 12, 2015, 04:58:29 pm
content: I think this whole wiring scheme is a Darwinist conspiracy...They want to use it to clean up the industry of careless people. One moment of carelessness and zap, you are fried.Now I feel I am being personally attacked...

author: SoundTech-LG
author_rank: Frequent Contributor
timestamp: April 15, 2015, 01:53:09 pm
content: Where I work someone in the past, a firmware engineer I have been told, decided to use the Resistor Color Code, or Transformer Wire code in his wiring scheme to power our 4 volt battery device off a 3 volt to 5 volt level shifter. So Black, Brown, Red, Orange,Yellow. All good so far. Well then... Black is + 4 Volts, and Yellow at the other end of the connector is Ground!It takes some getting used to...

author: electr_peter
author_rank: Unknown
timestamp: April 15, 2015, 04:28:51 pm
content: I had few scenarios where cable with identical pin-outs and connectors on both ends had different cable ordering on each end. 12V to 1V expecting circuitry or reverse polarity with "factory connector". Luckily, I always check cables so I spotted it before powering it up.