Orange Drop blows up....

-CB-

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P9034454.jpg

P9034455.jpg


Thought you might be interested in what a Sprague/Vishay Orange Drop looks like when it takes a poke from lightning.
This one is used as a DC (lightning!) blocker, letting the AC signal through... just like in amps, except used on a data transmission network that I service.  The addition of the caps to block DC was my idea, to help with the surge suppression scheme.  And it did protect the equipment.
 
R

RLW

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Out of curiousity, did it smell as bad as a filter cap that was wired in backwards?

Uh, not that I've ever personally done anything that stoopid...

:-\
 

GoDrex

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that's cool

so that thing kept the magic smoke from being released from other important parts.... good deal :)
 

dbw

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Why not get a surge protector?  And why use orange drops when a 5-cent electrolytic would work just as well?  :icon_scratch:
 

tfarny

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When I was in high school electronics (shop) class in the 80s, I took big capacitors and stuck them into electrical outlets, a couple times. Blew up real good after a few seconds. Don't tell anyone k.
 

dbw

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Must have been a shitty surge protector... I've seen motherboards with a row of blown caps back when I worked for Dell, but NONE of those people used a surge protector.

Attention non-computer guys: When the guy at Best Buy tries to sell you a surge protector along with your new computer, it's NOT a ripoff.  Buy it!
 
R

RLW

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My 3 Furman rack units are the best insurance I've ever bought.
 

-CB-

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Surge protection as follows - per conductor of data, of which there are two being used, although eight circuits on the cards.

input from field
half amp fuse in series
spark gap to ground
avalanche diode to ground
toroid in series
MOV to ground
--- end of first biard
ORANGE DROP in series
--- then on the next board
input from first surge board
1.2ohm nichrome resistor
MOV to ground
.1amp fuse
MOV to ground
1.2ohm nichrome resistor
--- end of 2nd board
ORANGE DROP in series
--- then on next board
input from the second surge board
MOV to ground
toroid in series
avalanche diode to ground
spark gap to ground
half amp fuse in series
--- output to equipment

All brought to earth grounds with less then 5 ohms EGR, as measured with my calibrated Megger EGR tester
Normally just the middle board is used, but in this case, I added additional protection at the customers request.  On his field units, he only has one of the "end boards" each, and these blew both half amp fuses, but no other damage.... for a total of about 70something fuses blown for one lightning storm.   Type 3AG half amp fuses can be had for $0.18each when bought in 1000 units at Mouser.   We get 10,000 at a time, and I'm not sure the price, maybe a penny or penny and a half cheaper.

This data line carries what is essentially a non biased carrier at about 1/2 volt level, so is not too easy to protect.  I think we do a decent job of it. 
dbw said:
Why not get a surge protector?  And why use orange drops when a 5-cent electrolytic would work just as well?  :icon_scratch:

This setup is about $50 per circuit in components (toroids are expensive), as mfg cost, and sells for well over $2000.  The electrolytic would not conduct well in both directions, hence the non-polarized Orange Drop (known for robustness, and its 600v rating).  The design is a classic back-to-back multistage protection scheme, designed to blow off excess to ground, and staged to give rise time preferences.  The fuses are there to protect the rest of the system in the event of a constant short failure mode of one of the transorbs, movs or sparkgaps.  Whatever hit, hit harder than 600v and hit longer than the heat could dissipate.  Check out the vaporized dots of aluminum inside the core of the cap..... neat!

 

ByteFrenzy

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1,177
-CB- said:
input from field
half amp fuse in series
spark gap to ground
avalanche diode to ground
toroid in series
MOV to ground
--- end of first biard
ORANGE DROP in series
--- then on the next board
input from first surge board
1.2ohm nichrome resistor
MOV to ground
.1amp fuse
MOV to ground
1.2ohm nichrome resistor
--- end of 2nd board
ORANGE DROP in series
--- then on next board
input from the second surge board
MOV to ground
toroid in series
avalanche diode to ground
spark gap to ground
half amp fuse in series
--- output to equipment

That is something you might want to put between your guitar and your amplifier when playing out in the open. Would protect your amp in case YOU were struck by lightning...

Seriously, though, this is heavy stuff - who're you working for, or is that a secret?
 
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It's not a power strip surge protector, but rather a large one that connects to a building's electrical system.  I've hooked one up before.  It attaches in parallel to a building's feeder and is a bypass to ground for any surge or spike.  In other words, a Furman on a larger scale.
 

-CB-

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Actually, the protector is quite small in size, fits into a box about 6x10x8deep.  What this works on is literally 9600baud datastream used to communicate with irrigation controls on golf courses.  We have literally 1000's of feet of wire buried along the course, and this is always subject to getting zoinkered from time to time each summer, when the storms come.  This datastream is sort of like regular "fax" or "modem" communication over phone lines, but there's no DC bias on it, since we dont need to do any fancy switching and its always connected.  So, no 48vDC on it, no pulsed 100vDC as a ringer... just pure clean vulnerable data.
 
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=CB= said:
Actually, the protector is quite small in size, fits into a box about 6x10x8deep.   

That's the size I was thinking, large compared to a power strip, and weighed about 50 lbs.  I installed one in a hotel.  It's main purpose was surge protection from lightning, but it absorbs any surge.  Large or small.  It has a surge counter, like an odometer, in it.  It was fed off of a 60 amp, 3-pole breaker in a sub-panel.  In this case, it was a redundant overkill.  The building had lightning protection.  The proximity of the service to transformer, which absorbs spikes anyway, was grounded, bonded, and had over-current protection, as well as being all underground.  Oh well, someone sold it, they bought it, I installed it.  The circle continues. 
 

-CB-

Senior member
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5,427
There are some really nice flanged MOVs available, that take about 30amps each, and crossover at 190-200v.... and are ideal for house power protection (or business too).

You need two of them.  Each would be wired from hot to neutral.

Nominal 117vAC wall voltage, can go up to 128-129 volts and be at its upper level of acceptable.  Since thats the RMS voltage, you need to consider the peak voltage.  So we take 129 times 1.414 and get 182 volts.  Hence the 190-200v MOV is where you want to go.

Interestingly, I got to play with a really neat line power recorder a few years go.  You plugged it in, and it recorded every event on the line, showing the voltage level (high or low) and the exact degree rotation through the cycle.  So you'd see YY-MM-DD-hh-mm-ss-CC-DD, and the voltage level and the event voltage level.  I got curious and set it up at "Fort Ceeber" and was slightly amused to see all the noise.  You'd get a lots of 10 and 25 and 50 volt spikes just because.  Then turn on a light... a 50v spike.  Turn OFF the light, and get a nice 2000v spike!  Wait till that A/C unit cycles down.... 5000v spikes over a few cycles.  Amazing that stuff doesn't get fried more often.  Its a time related thing.  Back to the customers.... we put those MOVs on his system, ran the analysis, and the noise his ice maker was making (and screwing up my stuff....) completely went away.  We'd see 5v spikes where 5000v spikes used to be.

And thats that!
 

jackthehack

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5,630
I made a lot of money replacing computer equipment in a building a long time ago when I was living in Boston. Got called in to consult by one company, wound up working for most of the tenants. It was the old customs house bldg. in Lynn, Mass. that had been gutted and completely refurbed and turned into office space. Things and components that never fried were failing on a regular basis, some big ticket items like the main board on a $75K copier/imaging system.

After getting tried of going back every couple of days, I started casual monitoring of the juice coming out of the wall sockets and saw some wild variations; the bldg. owners assumed the issues was coming from the grid as everything inside was brand new, so they jumped all over the power company who installed a power recorder like CB mentioned at the mains, which didn't show anything unusual while stuff upstairs was still frying. They wound up moving the power recorder INSIDE the mains and eventually found that the brand new elevator wasn't properly installed/setup and it's motor was acting like a giant capacitor, storing up charge and randomly discharging it at HUGE voltage spikes inside the bldg. Don't remember what the voltage values were, but they said it was like the building was repeatedly taking lightning bolt hits. A large line conditioner on the elevator circuit finally fixed the issue.

You never know where electrical surging issues may come from...
 

ByteFrenzy

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1,177
Reminds me of a little incident from the time when I was responsible for the data comms between the dealerships and the importer in Belgium of a very respectable brand of German automobiles. One of the dealers had some renovation works done and decided to do the electricity works himself. He wasn't too sure how it happened (which is pretty telling in itsef) but he managed to put 380V on the circuits instead of 220V. The result was that all five PC, three printers and our Cisco2503 were fried. Surprisingly their switch survived. Since it was the owner himself who achieved this, everybody just had a good laugh about it. If it had been a workshop mechanic he would probably have been fired...
 
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