Test Equipment Anonymous (TEA) group therapy thread

[mansaxel]

I sat down this afternoon on company time and made me some cables. We're going to evaluate a number of ways to transport time / frequency / phase over IP networks, and since we've got a bunch of routers with timing i/o there's a good reason to gather up the TE. I've already been promised a 465 from the Dungeon (actual name of stores) for doing lissajous patterns.

Since everything's so small these days and SMA already was claimed for GNSS antenna connectors, we're having to get SMB plugs. And those are on order. Other end of the cables is going to be BNC, though, and I took the opportunity to do HTML like it's 1999 (that's all I know how to do, and I see no reason to learn the crap that came after) and document how I do.

Constructive criticism appreciated.

[mnementh]

   Well, it's more insidious than that C... I looked at that chart when I was triaging the unit. I can only offer in my defense that I must have seen what I expected to see.  I have no doubt that I'm not the first poor sod that has happened to, either.

So now I'm going back to basics, and going to wire the thing correctly with a new cord. Then all that mess will be fixed proper; even if it is IEC colour-coded for you scone-eaters instead of North America, at least it will be colour-coded correctly.

First thing I did was cut the end off that defective cable, so it never gets used for anything except a source of raw wire.   

mnem
 

I don't get this. Why is it so important to know where phase and neutral are in a single-phase outlet? IMNSHO it's much easier to always assume both are lethal.  To think otherwise just opens for bad idea bingo season, like the All-American 5 and its guitar amp cousins.

It's not just being anal. It's aboot doing it right, and not making a booby-trap for the next guy that has to work on it. Work with the assumption that your work will outlive you, or worse yet, that you'll need to work on it again.

At least in NA, there are conventions we follow because not all electrical widgets have a grounded cord; we wire everything the same way with respect to Neutral vs Line as our plugs are polarized with an extra-wide Neutral prong & slot to act as if there was an actual GND as applicable. Neutral connects to Earth GND at the same bus in the breaker box, and is supposed to remain a single unbroken conductor all the way to the load; it is never switched.

Line (or Hot) is where you always put a switch. On things with sockets like lamp fixtures and the fuse holder seen above, Line or Hot always goes to the center pin so that it is hardest for a person to make contact with it and contact area is minimized, while Neutral always goes to the outer ring so it is at Earth potential. That way if little Johnny sticks his dick in it, the circuit path is across an inch or so of skin instead of through his chest and feet to Ground.

Color coding is, as we've been discussing, an international clusterfuck. But there are still conventions for safety's sake; these are there, and part of the electrical code, so we don't create booby-traps for others by layering poor wiring practice on top of other poor wiring practice, and so that when it does happen, the color-coding helps make it obvious.

Of course, you always want to be a one-handed electrician so as to not be the path to ground, you always want to work as if the line you're working with is live and at dangerous potential, and you always want to double-check with a meter. Those things are a given.

But there is still no excuse for not doing it right. Or at least what is considered "right" at the time (and place) you do the work. 

mnem
 

[mansaxel]

At least in NA, there are conventions we follow because not all electrical widgets have a grounded cord; we wire everything the same way with respect to Neutral vs Line as our plugs are polarized with an extra-wide Neutral prong & slot to act as if there was an actual GND as applicable. Neutral connects to Earth GND at the same bus in the breaker box, and is supposed to remain a single unbroken conductor all the way to the load; it is never switched.

And in Yoorp, most plugs of the "19mm between pin centres" family are non-polarized; the exceptions being Switzerland, France and Denmark. Which means that every appliance is a death-trap, right?

Alternatively, one can build appliances so that it does not matter which is which. 

:poke:

[SilverSolder]

At least in NA, there are conventions we follow because not all electrical widgets have a grounded cord; we wire everything the same way with respect to Neutral vs Line as our plugs are polarized with an extra-wide Neutral prong & slot to act as if there was an actual GND as applicable. Neutral connects to Earth GND at the same bus in the breaker box, and is supposed to remain a single unbroken conductor all the way to the load; it is never switched.

And in Yoorp, most plugs of the "19mm between pin centres" family are non-polarized; the exceptions being Switzerland, France and Denmark. Which means that every appliance is a death-trap, right?

Alternatively, one can build appliances so that it does not matter which is which. 

:poke:

Are all appliances double-insulated?

[mnementh]

Well, it's more insidious than that C... I looked at that chart when I was triaging the unit. I can only offer in my defense that I must have seen what I expected to see.  I have no doubt that I'm not the first poor sod that has happened to, either.

So now I'm going back to basics, and going to wire the thing correctly with a new cord. Then all that mess will be fixed proper; even if it is IEC colour-coded for you scone-eaters instead of North America, at least it will be colour-coded correctly.

Those grumps corrected and a proper ESD bleeder resistor in the GND wire for the handset; I just had to do something aboot that hot lead so committed a little Sharpie abuse to turn it bloo.

After discovering how well & truly fooked this thing was, I've gone back & rewired with a new cord in North American color code. Handset GND restored to original direct to Earth GND configuration after seeing inside of handset and noting close proximity of heater element to metal shell.

Oh, and that little bit of blue heat-shrink on the Neutral is just for you, C. 

mnem
 

[Specmaster]

Chinese strike yet again, when I unrobed my 858D, it was a little different inside to yours mnem, the circuit board had a different layout and all the mains cabling was done in red cables, including the transformer as can be seen in the photos so at least the switch was suitably wired in the "hot" red wire, yes I know it should be brown to be current but here's the catch, I'm pretty sure that colour code does not apply within control panels or equipment. I believe you will find that it is deemed that the person who is working inside the equipment should know what they are doing and that the equipment would be isolated any way.

But all the same for my own peace of mind, I decided on a more logical approach (at least to me), and decided to grab some small black cable ties and placed one at the terminal end of each of the neutral wires, pulled them up tight and chopped the tails off so that nobody would think that there was ever any other cable in it, job done.

Construction was just the same as yours, with an all steel enclosure and 2 plastic end trim pieces but mine had a proper IEC mains inlet rather than a cable hot snotted in.

[mansaxel]

Are all appliances double-insulated?

Newer ones that are ungrounded and possible to connect to a grounded outlet, yes.

Old ones, no. They aren't allowed to have a plug that fits grounded outlets. (The Schuko outlet is narrowed to the sides which blocks old circular plugs from mating. )

Grounded appliances, no, but that's not required and they're still unpolarized.

[bd139]

Chinese strike yet again, when I unrobed my 858D, it was a little different inside to yours mnem, the circuit board had a different layout and all the mains cabling was done in red cables, including the transformer as can be seen in the photos so at least the switch was suitably wired in the "hot" red wire, yes I know it should be brown to be current but here's the catch, I'm pretty sure that colour code does not apply within control panels or equipment. I believe you will find that it is deemed that the person who is working inside the equipment should know what they are doing and that the equipment would be isolated any way.

But all the same for my own peace of mind, I decided on a more logical approach (at least to me), and decided to grab some small black cable ties and placed one at the terminal end of each of the neutral wires, pulled them up tight and chopped the tails off so that nobody would think that there was ever any other cable in it, job done.

Construction was just the same as yours, with an all steel enclosure and 2 plastic end trim pieces but mine had a proper IEC mains inlet rather than a cable hot snotted in.

You can do what the hell you like inside it. I usually use yellow for live and neutral and switch both. That usually goes straight into a transformer or SMPS module. Green for earth.

[Specmaster]

Chinese strike yet again, when I unrobed my 858D, it was a little different inside to yours mnem, the circuit board had a different layout and all the mains cabling was done in red cables, including the transformer as can be seen in the photos so at least the switch was suitably wired in the "hot" red wire, yes I know it should be brown to be current but here's the catch, I'm pretty sure that colour code does not apply within control panels or equipment. I believe you will find that it is deemed that the person who is working inside the equipment should know what they are doing and that the equipment would be isolated any way.

But all the same for my own peace of mind, I decided on a more logical approach (at least to me), and decided to grab some small black cable ties and placed one at the terminal end of each of the neutral wires, pulled them up tight and chopped the tails off so that nobody would think that there was ever any other cable in it, job done.

Construction was just the same as yours, with an all steel enclosure and 2 plastic end trim pieces but mine had a proper IEC mains inlet rather than a cable hot snotted in.

You can do what the hell you like inside it. I usually use yellow for live and neutral and switch both. That usually goes straight into a transformer or SMPS module. Green for earth.

Thank you, you have just confirmed what I remembered from my motor control and switchboard building days.

[0culus]

Experimenting with (digital) oscilloscope photography after I was inspired to get out my D90 again after talking cameras with Saskia on discord.

[mnementh]

Chinese strike yet again, when I unrobed my 858D, it was a little different inside to yours mnem, the circuit board had a different layout and all the mains cabling was done in red cables, including the transformer as can be seen in the photos so at least the switch was suitably wired in the "hot" red wire, yes I know it should be brown to be current but here's the catch, I'm pretty sure that colour code does not apply within control panels or equipment. I believe you will find that it is deemed that the person who is working inside the equipment should know what they are doing and that the equipment would be isolated any way.

But all the same for my own peace of mind, I decided on a more logical approach (at least to me), and decided to grab some small black cable ties and placed one at the terminal end of each of the neutral wires, pulled them up tight and chopped the tails off so that nobody would think that there was ever any other cable in it, job done.

Construction was just the same as yours, with an all steel enclosure and 2 plastic end trim pieces but mine had a proper IEC mains inlet rather than a cable hot snotted in.

You can do what the hell you like inside it. I usually use yellow for live and neutral and switch both. That usually goes straight into a transformer or SMPS module. Green for earth.

Thank you, you have just confirmed what I remembered from my motor control and switchboard building days.

Okay... but did you confirm with a meter that hot and neutral were in fact wired correctly; not neutral to the switch and hot/neutral swapped at the pin header on the PCB?     This is clearly marked on mine, as you can see in the pic above.

Also, the power cord on mine is properly grommeted, as you can also see above; they just plastered the hot snot on it because these particular grommets are for a 1/8" thick panel, so tend to shift a wee bit on this 1mm thick painted sheetmetal. it looks like they did the same on the cord for your handset, quite likely for the same reason.


@bd139 - Sure, but I'm reasonably certain even a certified bastard like you wouldn't use yellow w/green stripe for any power conductor. 

mnem
Electrons may be very very small... but when they gang up on you, they always win.

[Neomys Sapiens]

A lot of what we discuss here surrounds labs/workshops at home or other permanent locations.  I've slowly been assembling a set of portable test equipment since I have a number of use cases for on the road tools and test equipment.  Anybody else maintain a set of portable gear specifically for mobile use on the road?

Yes, indeed. I posted pictures of some kits earlier. This is also the reason why I'm much interested in special solutions like the HP Locic Dart or the devices from PEAK and also the TekMeter.

BTW, the real fun starts when you have to plan for working OFF the road! Which is, for example, when your travel arrangements start to involve helo services.

[VK5RC]

A quick teardown showed mine wired similarly wrong; continuity test to the plug made absolutely certain. And really nerve-grating... the "hot" wire from the switch is made from wire in one of the universal color codes for a GND circuit. 

Those grumps corrected and a proper ESD bleeder resistor in the GND wire for the handset; I just had to do something aboot that hot lead so committed a little Sharpie abuse to turn it bloo.

It's worth noting that here in IEEE/IET Wiring Regulations land there's an official way of abusing wire when you don't have cable with the proper colour coding for what you're using them for and that is to fit sleeving of the appropriate colour at every point you terminate a wire.

So if you're wiring a lighting circuit where the blue conductor is used as a live conductor you're required to use brown sleeving at the points where it is terminated to identify it as a live conductor. Similarly you're required to sleeve any bare copper protective earth conductors (such as are found in twin-and-earth) with yellow/green sleeving. Although officially one isn't explicitly forbidden from sleeving a yellow/green PE conductor to another use, most people would say that it's a no-no but in Mem's particular case "needs must when the devil drives" - It's not like there's an NIC-EIC inspector lurking around the corner.

Officially here one can paint conductors to indicate the use but I suspect that Sharpie would be frowned upon as insufficiently permanent. (Especially if you coloured the hot phase blue given that brown is what the civilised world uses for hot on a single phase circuit, blue is neutral. I realise that in the strange world of North America white is neutral, black is hot* and that additionally blue is potentially a hot phase colour.)

*The world is big enough that at some point in history in one of the more backward states a black man will have walked past a white electrician getting his apprentice to learn to repeat by rote "Black is hot" and as he walks by, quietly he says to himself "Yes it is brother, yes it is" with a chuckle.

Fuck... you're right. It's not that the unit is wired wrong; it's a unconscionably defective power cord.  OTOH... just  look at the scrambled mess of colors on this chart; it's like Walt Disney threw up.

It's a right clusterfuck it is. Damn you C... now THAT is something I'm not gonna put up with.

mnem
thank Ifni electrons are colorblind...

I think that table is quite old esp wrt Aus standards

"Current Australian colour code- Single phase
Active – Brown
Neutral – Light Blue
Earth – Green/Yellow
Current Australian colour code- Multiphase
Phase 1 – Brown
Phase 2 – Black
Phase 3 – Grey
Neutral – Light Blue
Earth – Green/Yellow

Old Australian colour code- Single phase
Active – Red
Neutral – Black
Earth – Green
Old Australian colour code- Multiphase
Phase 1 – Red
Phase 2 – White
Phase 3 – Dark Blue
Neutral – Black
Earth – Green"

I haven't seen a solid green earth wire here for a decade or so.
Regards Rob

[mnementh]

That doesn't exactly reduce the above-mentioned clusterfuck factor even a tiny little bit, does it...?           

mnem
*toddles off to ded*

[VK5RC]

I think it puts Aus in the same category as EU and UK ie IEC, So one less category - hopefully 😂.
I wouldn't be surprised if NZ is the same as well. Tautech?

[mnementh]

For how long...? 

mnem
*knocks self unconscious with a positron mallet*

[cyclin_al]

At least in NA, there are conventions we follow because not all electrical widgets have a grounded cord; we wire everything the same way with respect to Neutral vs Line as our plugs are polarized with an extra-wide Neutral prong & slot to act as if there was an actual GND as applicable. Neutral connects to Earth GND at the same bus in the breaker box, and is supposed to remain a single unbroken conductor all the way to the load; it is never switched.

And even then the conventions are fooked!  All new ungrounded cords have polarized plugs, with one exception.  All new strings of christmas lights use non-polarized plugs, where neither prongs nor slots are extra-wide.  That appears to be no big deal, until you need a 2m extension between two strings of lights.  The polarized prong of the extension cord will not fit into the slot of the christmas lights.  I have spent an excessive amount of time searching for non-polarized extension cords, which appear to be no longer available (I have one, but have no idea how old it is).  I have spent an equal amount of time searching for polarized christmas light strings, which also appear to be no longer available (I actually have one, but have not put in the time looking for the fault in the LEDs or other part of the string).

There is another option, but is excessive consumerism.  That is to run a long extension cord in parallel with the first set of christmas lights and then use a power bar at the source.  That is totally not necessary, if the convention, as the dragon described, was actually followed.

Of course, this is discovered when the outdoor temperatures are now dropping to -10 C.

/rant

[VK5RC]

“We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganised. … I was to learn later in life that we tend to meet any new situation by reorganising; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency and demoralisation."
Petronius Arbiter cAD 40
I think this applies to 'standards' as well as organisations.
Depressing how things haven't improved over the last couple of millennia 😁

[tautech]

I think it puts Aus in the same category as EU and UK ie IEC, So one less category - hopefully 😂.
I wouldn't be surprised if NZ is the same as well. Tautech?

Here single phase switchboards and all associated wiring uses black for neutral whereas at ‘appliance’ level uses blue.
So single phase in NZ:
Phase can be red or brown.
Neutral can be black or blue.
Earth is green/yellow striped.

[capt bullshot]

Never mind standards, rules, law, organizations ... It's all made by foolish and greedy humans in order to gain power, money, chicks, ...

The only laws that universally apply to everyone and everything are nature's laws. Even politicians and lawyers cannot break them.

Especially regarding wiring colours: The electrons don't care about the colour if they want to electrocute you

[Brumby]

Truth be known - it's probably a bureaucratic contribution towards natural selection.   

[tautech]

Truth be known - it's probably a bureaucratic contribution towards natural selection.   

Tis a real shame the bureaucrats aren't top of the list of those falling to natural selection !
Fucktards, the vast majority of them !

[nfmax]

Virtually all wiring on aircraft is white.

That's to make it lighter, of course!
 

[Robert763]

At least in NA, there are conventions we follow because not all electrical widgets have a grounded cord; we wire everything the same way with respect to Neutral vs Line as our plugs are polarized with an extra-wide Neutral prong & slot to act as if there was an actual GND as applicable. Neutral connects to Earth GND at the same bus in the breaker box, and is supposed to remain a single unbroken conductor all the way to the load; it is never switched.

And in Yoorp, most plugs of the "19mm between pin centres" family are non-polarized; the exceptions being Switzerland, France and Denmark. Which means that every appliance is a death-trap, right?

Alternatively, one can build appliances so that it does not matter which is which. 

:poke:

Well, not all of Europe has round pin plugs. Not all NA plugs are polarised either. That aside, while non polarised mains connectors do not make an appliance a death-trap, they are not as safe as a polarised one with fuse and switch in the live.
In countries were polarised plugs are standard and wires colour coded, there is no excuse for not following the standard.
While most on here know why, for visitors, the issue is that if the neutral is fused or switched, with fuse blown all the internal mains parts are live with repect to ground. Two fuses don't help because you don't know which will blow.  Any un-polarised device should have at least a double pole switch or the same applies when switched off. Note this mostly applies to items intended to be serviced, permanently sealed devices like power supplies and chargers should not have internal connections exposed.

[Zucca]

I just used for the first time a

Code: [Select]

lambda *args, ... : 
in Python. It works but I do not fully understand why, was a copy&paste try from the web...