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BNC to alligator clip connectors were made for a function generator in our lab. Whoever made them decided that the ground connector wire should be red and the signal connector wire should be white.

As this is a lab for student teaching, I'm concerned at this non-standard coloring for leads.

Is this a potential safety issue? I suspect it might lead to equipment damage. Is there another aspect I should be wary of?

Ralph
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Peter K.
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    Yes, it is an issue. Don't think much of different aspects and replace the wires. – Eugene Sh. Feb 18 '22 at 15:10
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    Anyone who learns GND=Red will lead an interesting life. –  Feb 18 '22 at 15:27
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    Ironic, I'm working on a piece of Siemens gear where red = 0V and black = +24v. At least in the industrial sector, wire color means almost nothing. Sure, brown and blue *should be* 24V, and are for the most part (when *wiring* devices), but not always and especially not *inside* devices. I've even seen a 700V snubber wire as green with yellow stripe! – rdtsc Feb 18 '22 at 15:42
  • @user_1818839 If a short one! ;-) – Peter K. Feb 18 '22 at 16:21
  • @rdtsc Ouch! I would expect better of Siemens... – Peter K. Feb 18 '22 at 16:23
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    https://electronics.stackexchange.com/questions/36317/standard-wire-colors for some context. – Passerby Feb 18 '22 at 16:48
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    @PeterK. to be transparent, the "ground is potentially lethal" was not found in a Siemens product, but a now-defunct Olicorp product. – rdtsc Feb 18 '22 at 17:30
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    @user_1818839 _"Anyone who learns GND=Red will lead an interesting life."_ - As will anyone who learns GND=Black. Because black is ground, until that time it isn't :) – marcelm Feb 18 '22 at 20:43
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    Enter, thermocouples. I've always assumed that physicists decided what colors to use for TC wires, or maybe the child of a physicist. Maybe evil aliens. Maybe Doofenshmirtz. – Chris Knudsen Feb 18 '22 at 21:23
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    Sounds like a great teaching opportunity. Teach them that GND is usually black and red is usually +something Volts. Then ask them to verify that this is true for the signal generator as well. When they get unexpected results, use the opening provided by confusion to hammer the point home that you can't trust anything. – Dampmaskin Feb 25 '22 at 15:28

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Connecting the black to to same GND point as an oscilloscope or such will cause the function generator output to be shorted. That may not be a huge issue, but might damage the output.

Usually the BNC outer contact is connected to mains GND.

And not a good idea to teach students bad habits right at school, of course.

Ralph
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    Teaching them to blindly trust wire color is also a bad habit. – Passerby Feb 18 '22 at 16:35
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    @Passerby Teaching about road safety does not involve inverting traffic light colors. – Eugene Sh. Feb 18 '22 at 16:43
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    @EugeneSh. Teaching about road safety does include not blindly entering an intersection just because you have a green light. – Passerby Feb 18 '22 at 16:49
  • Or that it's okay to hit a jaywalker or someone cutting you off cause "you have the right of way". Or just because your GPS says you can turn left doesn't mean you can ignore the street sign saying no left turn, etc. Unlike traffic light colors which are fixed by laws like the federal uniformed traffic code, removable and relocatable wires on a bench are not fixed. – Passerby Feb 18 '22 at 16:51
  • Damage to a standard signal generator is extremely unlikely if the output is shorted to ground. I think the wire colors do not matter, I think what matters is to learn to read instructions how to connect wires instead of assuming. – Justme Feb 18 '22 at 17:46
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    @Justme It's not only about usage, it is about designing as well. If the student learns that the colors do not matter, their future designs will be willy-nilly as well. – Eugene Sh. Feb 18 '22 at 18:02
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    To my experience many young engineers are not that precise with colors etc, but once they get more experienced they start to be pedantic about visual indicators that have no actual function. That tells better than anything that it does give an advantage and it's something you need to learn :) – Ralph Feb 18 '22 at 18:43
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    Then there's AC vs DC. In NA a hot AC Line connection is typically a _Black_ wire AND/OR a Red wire. You can pick any color!... However the 0V (Neutral wire) must be marked White. Good times. Got a panel with both AC & DC? Maybe avoid black for your DC grounds. One just must know what they are doing. – Chris Knudsen Feb 18 '22 at 21:28
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    Seems clear that (a) colour code conventions are very valuable and (b) most people don't just rely on them. People aren't dim. They use loads of conventions daily *as well as* thinking for themselves. Too many analogies loses the crowd but: this paragraph adheres to a convention of starting a sentence with a capital letter. If I don't use them: everyone will carry on using their brain and understand what's written just as clearly. But the convention/etc is far better, eases working on that thing you checked. *not a good idea to teach students bad habits right at school* - spot on. – TonyM Feb 18 '22 at 22:12
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    @TonyM Very well said! Thank-you. – Peter K. Feb 20 '22 at 19:06