Looking for a new insulation tester

[Mick Bailey]

Just looking around at what's on the market - anyone got any recommendations for a handheld unit?

[J M Fahey]

What are your actual needs?

The "old" insulation testing standards called for a "Megger" which applied 500V DC (in the earlier ones, from a hand cranked magneto, go figure, in later ones from a SS flyback supply, Elektor or ETI published a project) and measured how many Megohms insulation you had.

But the new ones, which comply with IEC and other International standards, are usually called "Hipot Testing" and typically apply 1500V to 120V equipment or 3000V to 240V ones.

Usually beyond what a standard Service Lab has use for, specially because whatever they measure has no legal value, unless they are an IEC certified Lab.

[Mick Bailey]

I have an old 500v Megger, though one of the tinsel leads to the movement has recently broken and I can't find a replacement material to repair it right now. A back-burner project.

I just need something to assist with tracking down insulation leakage (mainly earth leakage) in 240v equipment. My old Megger has been invaluable over the years but maybe it's time to replace it.

EDIT: just spotted this. What an insane price.......
China Insulation Megohm Tester Resistance Meter Megger Megohmmeter 1010t - China Volt Meter, Amp Meter

[g1]

Who do you get to crank that thing 2 times per second?

[J M Fahey]

Not that high RPM, it's about fast hand egg beating speed.

And the price is insane, like the price of almost everything in China (at the OEM >1000 unit lot of course)

[g1]

Not that high RPM, it's about fast hand egg beating speed.

Right you are! Sounds faster than it really is. I just did a rough simulation with stopwatch and 240rpm is about egg-beating speed.
But I wouldn't want to be doing that on a production line for any sustained period of time!

[J M Fahey]

Right you are! Sounds faster than it really is. I just did a rough simulation with stopwatch and 240rpm is about egg-beating speed.
But I wouldn't want to be doing that on a production line for any sustained period of time!

Under Chinese Factory standards, that would be a lazy, leisurely job

For a free sample of actual working conditions, and that at a modern, technological factory, not those sweat shops churning out Mc Donald's Happy Meal toys, here's how speakers are made.

Try to stand the videos to the end, just once in your life (yes, just watching is unbearable) and imagine people doing this 12 hours a day, 14 days in a row (2 free days a Month and that because any less and factory workers suicide too much, not kidding).
Also explains the crazy low prices and monster production output.

Start with:
https://www.youtube.com/watch?v=P-pz...wnr6pz&index=1

You'll have to manually jump from part 4a to part 4b because there's a couple unrelated ones in between.

Worst is that it's technically correct, I have to go through the exact same steps to make a speaker (with logic differences between a guitar speaker and a 3 way car one) but clearly worker comfort and plain industrial health has not been included in the equation.

Enjoy

[Mick Bailey]

I saw a documentary about young girls who made the motor coils for hard drives. Their supervisor made sure they didn't look up from their repetitive task - they reckoned a glance up and back to the bench was three seconds and that amount of lost time meant they couldn't meet their daily quota. Many of the girls just about had enough time to get to their hostel and eat before collapsing in bed. 5am start to get to work the next day and a week of per year to visit their families. This was in a modern hi-tech factory, too.

[Mick Bailey]

That speaker sequence is pretty interesting. There's a good degree of diligence and care in their work (plus a lot more manual tasks than I expected) and it reminds me very much of the UK pottery industry where each operator performs a single, practiced operation day in, day out. It used to be for a lifetime, but no longer.

But there's no soul to the place. No smiles, banter or spirit. Just making speakers. But I guess those individuals are glad to be in any kind of work as an alternative to poverty. That's a very young workforce, too. I was looking around at similar footage in other factories and no-one seems to be over 17 years old anywhere. What do you do in China if you're 50?

[J M Fahey]

That speaker sequence is pretty interesting. There's a good degree of diligence and care in their work (plus a lot more manual tasks than I expected)

Yes, I'm an Industrial Engineer and see the job splitting and assigning very well made, with just a couple minor quibbles, such as excessive task division in one case , no need for one operator soldering the left tinsel lead and another to solder the right one and no need for 2 guys at the end of the belt to put speakers in layers on the pallets, just one is more than enough.
It's commendable thay "wasted" 3 operators for minor cleaning tasks, such as wiping excess epoxy and excess gasket adhesive.

And as said, operations are correctly made and probably exactly the same as what goes on in, say Celestion or Eminence ... although in the last case the work atmosphere must be much better.

For comparison, here's Jensen Italian factory.

https://www.youtube.com/watch?v=ny-ZYiuoHp4

Operations needed are essentially the same, and pace is still quite fast, although not frantic , the place is cleaner (not that the other is dirty) but the most important difference is that workers are allower much more complex tasks (as in 1 doing what would take 3 or 4 Chinese) so he gets less tired/bored/depressed and can feel pride in his work and the product.

I was impressed that each Jensen speaker (at least the 15" ones shown) are individually measured and each carries its personal parameters (including Thiele & Small) datasheet.

and it reminds me very much of the UK pottery industry where each operator performs a single, practiced operation day in, day out. It used to be for a lifetime, but no longer.

But there's no soul to the place. No smiles, banter or spirit. Just making speakers. But I guess those individuals are glad to be in any kind of work as an alternative to poverty. That's a very young workforce, too. I was looking around at similar footage in other factories and no-one seems to be over 17 years old anywhere. What do you do in China if you're 50?

If you are up to 50 you keep working in the garment/toy/shoes/whatever very low tech factory you got hired in when YOU were in your 20's ... 30 years ago.

Same thing.

You see people in their 20's now because we only look at electronics factories which were set up short ago.

All of them come from the same place: faraway (I mean it, up to thousands of miles away) small towns or hamlets where the ONLY option was working in the rice paddies.
Compared to that, working in a Factory, any factory, is Heaven