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WhatTheFlux!
05-22-2013, 09:09 PM
So I'm helping out at a company that was up in Canada, all of their machines are wired for 600 volts

Curious thing is I've been to auctions cross border and everything I looked at from temp-control units to dryers to process equipment... ALL of them 600 volts.

So what gives? Ya'll don't use 480? If not why?

Just curious...

Zero_Divide
05-22-2013, 10:22 PM
Its all a conspiracy to not pay workers compensation when someone gets ele tricuted.

See paying out a one time life insurance is cheaper than paying for healing and rehabilitation.

Black_Moons
05-22-2013, 10:24 PM
Oh, dem volts are just bigger up here in canada. Don't know why you americans use that piddly 120v all over the place. Here we just crank er up to 600v and let er rip.

Jimmer12
05-22-2013, 11:18 PM
There is everything from 208/220/440/480/575 and 600 volt in use up here but I would say 220 and 600 are the most common. 600 makes sense since amps are inversely proportional to volts so if you run higher volts you use less amps and therefore can use smaller gauge wire and fuses.

darryl
05-23-2013, 12:05 AM
We wanted to use an even 1000 volts, but someone with a lot of foresight realized that offshore wire insulation would probably not be up to the task, and we were committed to supporting the economy in all parts of the world.

As it turns out, they were right. Things like offshore motors have shown that they aren't even up to handling 110.

WhatTheFlux!
05-23-2013, 12:05 AM
There is everything from 208/220/440/480/575 and 600 volt in use up here but I would say 220 and 600 are the most common. 600 makes sense since amps are inversely proportional to volts so if you run higher volts you use less amps and therefore can use smaller gauge wire and fuses.

Ok, thanks for the answer.

I figured it was something like this, however I am going to tell folks that it's because Canadians use metric volts, and that the actual voltage is 589.37418 volts. However they round it up to 600 volts to make room on the name-plates.

macona
05-23-2013, 12:11 AM
There is 575 down here too. You usually find it in places like mills where they have big, big, motors.

legendboy
05-23-2013, 12:21 AM
I will say that everything industrial hvac up here is 575 (600)

flylo
05-23-2013, 12:41 AM
Go big or go home, eh?

bandsawguy
05-23-2013, 06:45 AM
Ever where I work seems to be 600v. We constantly import machines that are 230v. I buy a lot of transformers. What kills me is the electrical inspections. The machines come in with overloads but no short circuit fusing. Apparently short circuits only occur here in Canada.

motorworks
05-23-2013, 06:54 AM
Hi
Beer brews better at 600v !

John Stevenson
05-23-2013, 07:26 AM
Hi
Beer brews better at 600v !

That accounts why the Budweiser plant runs on 110v then ?

Dr Stan
05-23-2013, 08:46 AM
That accounts why the Budweiser plant runs on 110v then ?

Budweiser makes beer? So that's what they call that off color water. I'll stick with my amber ale.

GNM109
05-23-2013, 09:18 AM
When we take over and make Canada our 52nd state (right after Puerto Rico) the first order of business will be to lower the voltage to the exact same reading that I get in my shop. That would be 252.6 VAC.

We will of course do this by Executive Order. That's the same method that we use for legislation on all of the more important matters. :D

philbur
05-23-2013, 09:38 AM
Less copper more deaths. No sure what makes the best sense in that one.

Phil:)


600 makes sense since amps are inversely proportional to volts so if you run higher volts you use less amps and therefore can use smaller gauge wire and fuses.

bob_s
05-23-2013, 09:45 AM
Less copper more deaths. No sure what makes the best sense in that one.

Phil:)

We are very much dedicated to maintaining a low population density.

When you take into account the increased illegal immigration from third world countries, and their propensity for propagation, the use of higher voltages seems to be more humane than just killing them with firearms.

A.K. Boomer
05-23-2013, 09:53 AM
Ever where I work seems to be 600v. We constantly import machines that are 230v. I buy a lot of transformers. What kills me is the electrical inspections. The machines come in with overloads but no short circuit fusing. Apparently short circuits only occur here in Canada.



"I buy allot of transformers"

Whoops there goes both the higher efficiency and the copper savings:p not to mention more clusterfuque of stuff to go wrong... Just sayin,

The big concern is keeping it high on the power lines for transport and efficiency - then after that either way your going to have to pay the fiddler in one form or another... unless you keep even the simple stuff in household use extremely high, then you will be paying the fiddler in an entirely different way with burial expenses and such...

Stern
05-23-2013, 10:20 AM
When it comes to industrial, the two used the most seem to bee 600 (575) and 440. 600 seems to be standard in huge plants as its a lot easier to "distribute" around the place, while smaller places use 440 (almost every elevator I have worked with uses 440). There are definite benefits to using higher voltages, as the motor size (physical) drops as the voltage goes up for the same HP (winding wire smaller as the current is lower). Also, its a bit of a myth that the higher voltages are more dangerous (when talking about V below 1000V and not having to deal with "arc transmission). Once the voltage becomes large enough to break the skin resistance, the killer is current, not voltage. You can get fried just as easily with a 48V Bell Canada battery stack as you can with 220 or higher. Been sent across the rooms more times than I can count with 120/220, and it hurts just as much as the time I was sent across the roof with a 440V elevator feed.
So, having machines with higher voltages (for the motor) makes a lot of sense, as it cuts cost and weight of the machine big time.

A.K. Boomer
05-23-2013, 10:38 AM
higher voltage spikes are more likely to stop your heart, there's not a whole lot of current (amps) in a car's 45,000 volt ignition system at all, but have one hand on the engine block and one touching a plug wire and run it through your chest and walla - you could just be fitted for a pine box...

I agree with major machinery and it being more efficient - but if your importing other machinery that's lower and having to run small stepdown transformers then your eating your lunch and creating complexities... like Bandsawguy says' "I buy allot of transformers"

Stern
05-23-2013, 10:46 AM
Not necessarily true, as its like a Russian roulette game with many things having to be in place. I have been zapped by more ignition systems that I can count with no ill effects (I use my hand to check my bikes spark when I have problems, and apart from a jolt Im still kicking). You will find when it comes to electrocution, a momentary jolt usually causes no damage most of the time, its the sustained current flow. I have know many hydro workers that have been zapped (we are talking 30,000V +) and while usually having holes blown in their hands and feet, they survive. I myself would rather take another 440V hit than get zapped with a 120VDC emergency lighting battery bank, as DC tends to "lock you on".
The required current to stop the heart is only around 10mA, and you can get that from any voltage source. The only impart voltage has is supplying enough force to break the skin resistance (9VDC battery can kill you if you brake the skin, while stun guns are considered non-lethal and generate about 500,000V)

Rule of thumb is "electricity is our friend", but if you don't respect it you WILL pay.

A.K. Boomer
05-23-2013, 10:53 AM
The required current to stop the heart is only around 10mA,


You said it not me:p

Stern
05-23-2013, 11:02 AM
Yep, its the current that kills. While I wouldn't condone checking your 600V feed using the finger test, I would recommend that electricity is given the respect it deserves, as 120 can kill just as fast as 600. So for me, I worry more about "getting zapped" than how high the voltage is, as that seems to keep me pretty safe :)

A.K. Boomer
05-23-2013, 11:15 AM
Sorry - just like you can't make horsepower with torque alone and need RPM's you cannot get the current there without volts,

Volt's is what makes it possible for the current to run, as the voltage goes up so does the risk as like you stated it takes so little amperage to stop the heart - so the voltage is the big variable of concern --- why? because it's what allows the connection to result to begin with -
my hands have been so dry that I cannot even feel 110, yet if it was 440 it would not matter as the voltage would seek out the "juice" underneath my skin and make the conductivity possible - and the lower rated amperage of the 440 does not matter, all you need to know is it's a whole hell of allot more than 10ma and its having no trouble getting delivered,,,

Fact - when the volts go up so do the risks... another fact, if the 45,000 volt car plug wire was DC continuous and you had one hand on the engine block and one on the wire we would not even be having this discussion...

motorworks
05-23-2013, 11:21 AM
And to add.....I got some of my best buys due to 600v 3 phase...
at trade school auctions years ago most of the general public would not touch
anything that was 3 phase and over 220 volts....
Have to confess I often checked the plates as I looked over a machine and said out load
" this one 3 phase 600"
(even if it was not).
;)

RancherBill
05-23-2013, 11:24 AM
So what gives? Ya'll don't use 480? If not why?

Just curious...

You guys started this AC distribution thing.

A Canadian Engineer re-ran the numbers and corrected your mistake!

bborr01
05-23-2013, 11:27 AM
The plant that I retired from had a huge Centac 4 stage compressor that would supply all the air needed to run a 40 acre factory. While it was being rebuilt and the cage that housed it was open, I went inside and had a look. The motor had an armature about 6' diameter. Motor tag read 7,000 volts ac, 4,500HP. We also had our own power plant so 7,000 volts was not a problem.

Brian

kf1002002
05-23-2013, 11:47 AM
I'm an 81 year old Canadian, I've done industrial type electrical work since I was a teenager and it's almost all 550/575/600 for low and medium power here. There's break point in the code for insulation at 750 volts so that's one reason higher voltages (>=1000) are only used for large motors. I'm not sure why Canada got started on 575 volts but as far as I'm concerned it's worked out OK. I see no increase in danger at this voltage and with lower current there is less of a blast of fire in case of a fault. This blast can be more dangerous than the electrical shock.

And, Stern, while it's true the winding wire is smaller for lower current at 575 volts there must be more turns for a given HP so the total amount of copper may stay about the same.

480 volts may be a bit more flexible in that a transformer can have, say 4, 120 volt windings; then the same transformer can be connected for 120v with all windings in parallel, 240v with 2 in series then the 2 series groups in parallel or 480v with all 4 in series. That seems to me to be an advantage for the 480v system.

It's a bit fallacious to compare the shock hazard from a power system, 480 or 575v with the shock from a spark plug, mosquito zapper or some such small high voltage source as the current from the spark plug, etc. is very limited and as soon as current starts to flow the voltage collapses. For a power system the available current is usually many 100's or 1000's of amps so the damage done is much greater.

Having said that, I can recall an accident which I investigated many years ago: A quarry workman was firing a blast and took shelter
sitting under one of the large trucks. The blast threw the firing wires up and over a 110kv power line and the other end on the truck. When the workman got up he bumped his shoulder on the truck so got a major shock and burn. It should have killed him but when
I visited him in the hospital he was in good spirits with only a big bandage on his shoulder. He was very lucky.

I guess that's enough expounding for the moment

Ken

MaxHeadRoom
05-23-2013, 11:48 AM
I agree with major machinery and it being more efficient - but if your importing other machinery that's lower and having to run small stepdown transformers then your eating your lunch and creating complexities... like Bandsawguy says' "I buy allot of transformers"

A position I had once, required laying out specifications for a large Canadian companies machinery purchases, I would always request that U.S. and any other foreign suppliers supply 575/600 v rated equipment, where possible.
In many cases the machinery was internally fitted with a step down transformer anyway, so this could be substituted with a 575 version, and any 440 motor would be changed to 575.
This was in an effort to avoid all the 600/440 transformers that were appearing with every machine!
I believe if any company want to pick up export business, they should cater to the market they are selling to.
Max.

Evan
05-23-2013, 12:01 PM
It's a legal thing. To work on systems that run higher than 600 volts you need better credentials. With systems 600 volt or lower you can use in house trained and qualified people. To work on higher than 600 you need a fully trained high voltage qualified electrician to even touch anything to do with the system wiring.

philbur
05-23-2013, 12:20 PM
Ya, and current is proportional to voltage.

So you are saying 120VAC is as dangerous as 600VAC. I'm glade you'r not doing my electrical work.

Phil:)


the killer is current, not voltage.

Evan
05-23-2013, 12:30 PM
Current is proportional to voltage AND resistance. It's all about voltage plus resistance when it comes to electrocution, especially skin resistance.

MaxHeadRoom
05-23-2013, 12:35 PM
All this talk of electrical shocks, by far the highest number of electrical accidents each year are due to flash-over burns.
http://www.electricalreview.co.uk/features/5010-11509
Max.

Evan
05-23-2013, 12:39 PM
Around here for quite a while it was due to idiots trying to steal live electrical wiring in substations and wiring vaults. A number of them turned to charcoal. They are supposedly cracking down on the scrap dealers lately so there haven't been as many.

A.K. Boomer
05-23-2013, 12:51 PM
I was just about to bring up the difference,

The thing with massive amps and low volts is this - it's easy to let down your guard because you think your "safe"

and really you are, until you bring a highly conductive tool into the 12 volt battery bank and ground it out,,, then boom. even though you could touch the "ran in parallel" final leads with your hands and get no shock what-so-ever,,,

in low voltage high amps your not the critical factor - the highly conductive tool is, and it along with the lead or copper terminals will turn into a molten blast of liquified metal...

BUT, in high voltage and even far lower amps the tools not the only thing that's conductive - you are,,,
you watch everything as everything is critical, Evan just said it - it's all about skin resistance - and once it decides to breach that barrier it's home free for conductivity, and the higher the volts the easier that barrier is breached...

Black Forest
05-23-2013, 12:56 PM
The Canadian volts aren't as big as US volts. That is why they need more of them to get the job done. 120 vs. 600 Those Canadian volts must be real small.


I got zapped a year ago last January with 380 volts. It is only just now that I am getting back to normal. It caused quite a bit of scarring internally according to my doctor. A lot of heart problems because of the shock. For over one year I had nearly zero energy. Only my cantankerous hard nature let me function at all.

Paul Alciatore
05-23-2013, 01:53 PM
The factor that is probably most related to the damage done by an electric shock is the amount of energy delivered to the various organs of the body. Power may be a better word here as time is a factor because if a certain amount of energy is delivered over days or weeks it may have no noticable effect while if it is delivered in a short time, like one second or less, then the effects will be much worse.

The argument over Voltage vs. current is really useless unless all the factors that are involved in the delivery of the energy to the various organs is discussed in detail.

That being said, I have been bit by 115 VAC and by 40,000 VDC and obviously survived both. The 40 KV went through and through; I had the burn marks on hand and foot to prove it. I can tell you that the 40 KV left me in a shaken state for four or six hours afterward while the 115 V can be shaken off in a few minutes. I was fortunate in that the 40 KV came from a limited current source and it probably shut down after the capacitors discharged (through me).

If the other factors are unknown, then I am firmly convinced that the higher the Voltage, the more danger you are in from being shocked from it.

MaxHeadRoom
05-23-2013, 02:18 PM
http://hypertextbook.com/facts/2000/JackHsu.shtml

A.K. Boomer
05-23-2013, 03:02 PM
And still the fact remains, skin is an insulator of sorts, esp. when compared to our more conductive "juicier" centers...

that being said Volts are the most critical part of the equation when it comes to current being able to pass through us - if this was not true then me and every single mechanic ever living would be dead just by simple car battery installations - and in fact car batteries are a really good example to use as they have copious amounts of on demand relentless amperage - but their very safe for us to work around bare hands and all and will not electrocute us,,, just don't drop your breaker bar across one... or make two little + and - paddles and place them on each side of your open heart...

platypus2020
05-23-2013, 03:44 PM
575 (600) vac is the reason I have to carry a Lincoln Invertec V-275S welder in the service van, along the Canadian border, paper mills, co-gens and a few other facilities, 575 vac is their standard. I carry the Lincoln (208/230/460460, single or 3 phase) for the 575 vac ability and also a Miller Maxstar 200SD (120/208/230/460, single or 3 phase) for the ability to run 120 vac.

quasi
05-23-2013, 04:19 PM
It's a legal thing. To work on systems that run higher than 600 volts you need better credentials. With systems 600 volt or lower you can use in house trained and qualified people. To work on higher than 600 you need a fully trained high voltage qualified electrician to even touch anything to do with the system wiring.

not in Alberta anything over 240v you need a Sparky, most Commercial and Industrial sites you need a Red Seal Sparky period.

600v is the limit of voltage for standard type (R 90 , TWH, ...) WIRE insulations. The higher the voltage the less amps for the same energy, ie a 20 H.P. 208v 3 phase motor will have a FLA of 60 amps or more, a 600v motor will draw 20 amps, letting you use smaller wire, contacters etc.

philbur
05-23-2013, 06:23 PM
Yes but whether I grab a pair of 600V wires or a pair of 120V wires my body resistance is the same. So the current is proportional to the voltage.

Phil:)


Current is proportional to voltage AND resistance. It's all about voltage plus resistance when it comes to electrocution, especially skin resistance.

Evan
05-23-2013, 06:35 PM
not in Alberta anything over 240v you need a Sparky, most Commercial and Industrial sites you need a Red Seal Sparky period.

Yes, but you may also have house trained people working under the supervision of a licensed electrician. Same as when I worked on aircraft. I was not a certified AME but as long as there was one supervising my work that was all that was needed.

Evan
05-23-2013, 06:37 PM
Yes but whether I grab a pair of 600V wires or a pair of 120V wires my body resistance is the same. So the current is proportional to the voltage.

That depends on how much you are sweating about working on the higher voltages....

philbur
05-23-2013, 06:41 PM
True, but then that would make higher voltages proportionally evan more dangerous.

Phil:)


That depends on how much you are sweating about working on the higher voltages....

Mark Rand
05-23-2013, 06:46 PM
Either 600 or 120 will kill. 110 centre tap earthed tends to be a lot more survivable because you're more likely to only see 55V.

Over here we're 240/415 (tending towards 220/380 on new installations). I've had belts of 240 and 110 and 110 scares the sh!t out of me, but that's only because several of those shocks were quite bad and all of the 240 ones were minor.

At the end of the day, even the ringing voltage and current on a phone line can kill. As the instructions for operators of open switchgear at GEC Machines (ex BTH) said:- "Operators must keep one hand in their pocket at all times when operating switchgear." Think about it.

PS. 575-600V doesn't seem to be a nice SQRT(3) factor from a usable lower voltage. Is it stepped down from 1000V, with 220-240V single phase derived completely separately?

A.K. Boomer
05-23-2013, 07:20 PM
True, but then that would make higher voltages proportionally evan more dangerous.

Phil:)

So now Evan is dangerous?

Higher voltages makes it easier to overcome insulation properties (skin) and in extreme high voltages it even overcomes the insulation properties of air - nutherwords you don't even have to come in contact or be anywhere near it and it will make the leap - try that with 110,,, the higher you go - the more likely the current will be able to make the jump - be it between your skin or the airspace between you and the high voltage,,,

flashlight batterys have way more than just milli-amps - but you don't hear of too many people getting electrocuted whilst changing them now do you??? ahhh so it's a voltage thing ain't it? brilliant deduction.

Stern
05-23-2013, 07:39 PM
Well, guess as usual, I didn't get my point across as intended lol. There is obviously a relationship between voltage and current (when taking the resistance of a body into account), but my point was it doesn't matter if its 110V or 600V, if the skin threshold is broken and current flows the difference in the voltage doesn't matter (as 10mA can be lethal, makes no difference if your flowing 10A or 20A, if the path is right your screwed either way). This does NOT mean higher voltages are more dangerous. Stun guns deliver thousands of volts but not enough current to do damage, same with a car ignition, current is too low.

BTW, while a car battery is safe to play with, I would hate to see someone feel its safe when a bank is set up to supply 120VDC (as in emergency lighting systems). The approx skin breakdown voltage (depends on skin dampness) is about 48V, so anything above that will generate a current flow. You can use your hands to jump a 12V car battery with no issues, do it with a 120V bank of batteries and you WILL die. I would rather jump a 45,000 V feed line than a 120VDC bank, as the later has a lower survival chance.

Anyway, the main point I was trying to make was dont assume because the voltage is low its safe, as I seen people die making that mistake.

Stern
05-23-2013, 07:43 PM
So now Evan is dangerous?

Higher voltages makes it easier to overcome insulation properties (skin) and in extreme high voltages it even overcomes the insulation properties of air - nutherwords you don't even have to come in contact or be anywhere near it and it will make the leap - try that with 110,,, the higher you go - the more likely the current will be able to make the jump - be it between your skin or the airspace between you and the high voltage,,,

flashlight batterys have way more than just milli-amps - but you don't hear of too many people getting electrocuted whilst changing them now do you??? ahhh so it's a voltage thing ain't it? brilliant deduction.

Well, if you feel suicidal, you can try sicking a wire in one shoulder and a second in your opposite hip (must break the skin and enter soft flesh). Then hook the wires up to a car battery or even a small motorcycle battery. The only reason you don't get electrocuted from small batteries is they can break the skin barrier (unless they get above 50V, then the whole game changes).

A.K. Boomer
05-23-2013, 07:58 PM
I already covered that in post 38 with the heart paddles :p

"that being said Volts are the most critical part of the equation when it comes to current being able to pass through us - if this was not true then me and every single mechanic ever living would be dead just by simple car battery installations - and in fact car batteries are a really good example to use as they have copious amounts of on demand relentless amperage - but their very safe for us to work around bare hands and all and will not electrocute us,,, just don't drop your breaker bar across one... or make two little + and - paddles and place them on each side of your open heart... "

12 volts is very safe - 110 is safer than 440...

darryl
05-23-2013, 08:51 PM
Wherever you live, you deal with the situation at hand. Canada is so vast that a short circuit is virtually useless. They all have to be long circuits, so the voltage has to be higher. We don't need breakers since most of our power is very friendly- it comes from Peace river :)

Fasttrack
05-23-2013, 10:30 PM
This is a hilarious discussion. Apparently some of you feel that 600 volt distribution is a poor choice because it is more dangerous. Maybe you need to do a little more investigation as to how electricity makes it to your breaker box.

Are high voltage systems more dangerous than your doorbell circuit? Yes. Does the benefit outweigh the risk? Yes. Is a 600 volt distribution practical for a home shop? No.

By the way, where I come from 600 volts is still considered low voltage. ANSI considers 1000 to 35000 volts AC to be medium voltage and I helped remove and rebuild a motor than ran on 4160 volts. I've also worked on high voltage DC and high voltage RF systems. Sometimes there is no practical substitute. Life is dangerous, get over it.

A.K. Boomer
05-23-2013, 10:37 PM
FT - eat a fuquing snickers bar - we've already covered all the pro's and con's while you were taking your afternoon nappy-poo...

JRouche
05-24-2013, 01:09 AM
Ok bad etiquette for web sites. Commenting unless I read many replies. I read ten and it took 10 minutes. Im a very slow reader. But Id like to get involved.

I look at our (south of the boarder) 110-115-120VAC as a decent household supply. Its down the middle for inductive or resistive loads and doesn't hurt too much when glanced on. But can kill you dead if clamped on.

Think of the supply back when it was DC. Great resistive supply, lots of current delivered for cheap at a low voltage. But then inductive loads (motors) were being used and now the DC doesn't look so good. Now they have to bump up the voltage and reduce the current for the longer distances to the plants. Remember, the DC was at a low potential (voltage) but relatively high current. Thats why the first consumer loads were light bulbs and heaters. Electricity brought us out of the darkness. I'm a Tesla fan from way back. He was playing with AC while Edison was doing his thing with DC. Love Edison also by the way. I lived in New Jersey as a kid. Took a field trip to the Edison museum.

So AC is the way to go. Motors love higher voltages. Actually really high potential. So I get why 600VAC is used. Remember motors are levers. So if you have a larger wrench on the shaft of a motor it will do more work right? Well 600vac is a larger wrench than 220vac or even 440vac. Our brothers to the North have us beat there. We tend to over current our motors.

Love my Canuck friends. While in the Navy hunting for Russian Subs we got to pull along side of our Sister Ship from Canada. Was great but I forget if it was the Canadian Ship or the British Ship where we were along side of when they gave me a tour of the hull.

YUP, full of beer :) Now thinking it was the Brits. It was in the Persian Gulf or IO. It was hot and still. Came aboard and had a cold beer. We are a dry at sea Navy. Great times with the Brits and the Canucks for six years.

Not just old Sea stories (though I have a few). A way to get to high voltage AND high frequency supplies. Again Tesla nailed it (oh but their cars are obscene, he would be rolling in his grave).

On the ship we had some 440vac/400hz motors. They were very small for the workload. They were the most efficient motors on the ship. Problem? Most everything else used 60hz. I get it, its dangerous (400hz likes to make friends, it reaches out). But that's why 60hz is around.

Safety has to be there. 600vac at 60 cycles is a great Watt system. You get some torque from the extra voltage and it wont reach out and grab you. You still have to latch on to get killed. But the brush burn on the back of yer hand might be a lil more scorched, at leased you didnt grab a wire. People! Do NOT grab any wires that might be in play. I work on energized circuits. Have for some time. They are hot. Treat them as so, hot or not..

WoW! Been talking for sometime. Time to get off.

Oh? LOL The Ship! We had a circuit that I serviced, it was one of many tubes. This baby ate 50amps at 50kv (50,000 volts), yup it was eating 2.5MW to push 1MW out the feed horn. We had to work on her live to check the power supply. We checked at the tube (it was a klystron). Very simple tube but unlike yer Dads TV tube. All metal, would create X-Rays if powered up ( it was at 10GZ +/-the secret freqs).

We had some Magnetrons that wanted a service also. But they were much more civilized. Their associate circuit cards were more of a pain. Old time Navy. Coming up on 30 years. They must have advanced. Phased Array, old tech (dipoles on a panel) was new in 1984. Now all the Ships use PA radar. The software made that happen.

WOW!!! I have completely broken the forum etiquette. I have been drinking (love retirement) and posting blaa, blaaa :)

The way I look at it. I have been here for more than a second. I get to go off the rails... Love the topic. JR

Evan
05-24-2013, 01:22 AM
I used to service equipment on the Canadian destroyers. Weird power system. 120 vac split phase with the hull at neutral and a pair of 60vac legs. We had to use a honkin big isolation transformer to give the machine a floating neutral that wasn't at 60 volts above machine ground. It may have had something to do with magnetic field equalization. No idea if it is still like that, all those ships have been totally refitted or are out of service since then in the early 70's.

macona
05-24-2013, 02:13 AM
Around here for quite a while it was due to idiots trying to steal live electrical wiring in substations and wiring vaults. A number of them turned to charcoal. They are supposedly cracking down on the scrap dealers lately so there haven't been as many.

They passed some scrap laws down here that have cut the thieving back somewhat. Simplest was they scrappers only pay with a check for non-ferrous and then they mail it to you and there is a time period as well.

A year or two ago my dad was walking out to his shop in the evening, he had been in the house watching TV. When he got back to the shop there was a guy in there, at first he thought is was a customer, then he noticed the pile of electrical cords by his feet. The guy took off, my dad called the police. The idjit left a beer can so they got his prints. They did find him. My dad got to rewire the cords on a bunch of stuff. Cant remember if any of the cords were live, I think they were.

Fasttrack
05-24-2013, 02:31 AM
FT - eat a fuquing snickers bar - we've already covered all the pro's and con's while you were taking your afternoon nappy-poo...

Yep. You guys covered the pro's and con's alright...


Less copper more deaths. No sure what makes the best sense in that one.

Phil:)

:rolleyes:

You're awfully defensive, AK. Maybe you're the one who needs to be taking afternoon naps...


I agree with major machinery and it being more efficient - but if your importing other machinery that's lower and having to run small stepdown transformers then your eating your lunch and creating complexities... like Bandsawguy says' "I buy allot of transformers"

This is assuming that you are putting a step down transformer for each device. If you are going to outfit your factory primarily with machines that only run on 230V, then you should outfit the factory with 230V service, which is a common voltage in Canada (from what I am told). Alternatively, if you have one or two specialized machines that run at 600V, then you install one big pad mount transformer and run 230V service from that for all smaller machines and run a separate high voltage bus for the special machines. (Or if you only have 230V available you can run the transformer backward - I am currently running a Kearney Trecker 2D this way. 208V service goes a transformer that kicks it up to 480 for the mill). That's how many factories, office buildings, laboratories etc operate. They get 480V service or higher and have their "own" transformer on site to step down.

philbur
05-24-2013, 06:32 AM
Was it ever otherwise?

Phil:)


So now Evan is dangerous?

Doozer
05-24-2013, 07:35 AM
Canadians use metric volts, and ...

Volts is a metric unit of measure.

--Doozer

J Tiers
05-24-2013, 08:49 AM
This IS a silly discussion. A few points...

1) Someone suggested that the 600V was less of a problem for arc flash due to lower current.

THIS IS NOT ACTUALLY TRUE

The important factor for arc flash (and short circuit current) is the "impedance". Every transformer, and the wires, etc contribute series resistance and reactance (usually inductance) that will limit current.

When you want to know the short circuit current (or arc flash) capability of a circuit, you look at the series impedances and then the short circuit current "threat' is (in simplified form) the circuit voltage divided by the impedance. The impedances need to be "referred to" the shorted circuit to be correct. Voltage is important as well, because at low voltages, the impedances are usually too large to develop a high power arc.

Higher voltages usually have fewer and lower impedance transformers in series (because they are higher power), so they generally have more potential for arc flash. And they have (obviously) the voltage to initiate an arc and sustain it over some distance "between electrodes". A higher power arc is a lot more damaging.

yes, of course fusing/circuit protection is also important.... And, BTW, high voltage fuses are much more expensive....

As for the 120V etc,

a) the US uses 240V, we just split it into 2 120V sections for *some* loads. Any higher power "house" loads are on the 240V, such as central air conditioning, electric heat, electric car chargers, etc.

b) yes, higher voltages IN PRACTICE usually are both more damaging to "get across", and have more tendency to cause electrocution.

c) Yes, even a low voltage CAN cause electrocution, i.e. heart stoppage, although as the voltage gets lower the chances decrease until you basically need a laboratory setup to manage to do it.

quasi
05-24-2013, 01:31 PM
the phase voltage of 600v line voltage is 347v. 347v is very common in Canada for lighting in Commercial and Industrial lighting. Getting "bit" by 347v does not sting like 120v, it is actually painful.

Jon Heron
05-24-2013, 02:59 PM
These discussions always amuse me, filled with with very factual sounding information from people who haven't the foggiest idea what they are talking about and they are the ones who always debate the hardest lol I have made it a rule to not get involved in these debates cause its alot like putting your head in a vise...
Here is some info that may add to the discussion.
120V kills more people world wide than any other voltage, its not enough to throw you but it is enough to keep you hanging on until your dead. I am a 3rd generation electrician who has been on the job for about 25 years now and I have had many shocks, the worst of which was 120V, it pulled all the muscles in my chest (which made breathing very painful) and very nearly killed me, had my body weight not pulled me off the stove I would be dead. But yes, 347/600V hurt's like hell and will typically leave a burn (as I am sure 277/480v does too), however it will also typically throw you off and the injury from banging your head or falling is usually worse then the shock itself...
A 480V circuit is no safer then a 600V circuit, period, to say otherwise shows ignorance. There is also no difference in size between a 600 or 480v motor and up here many are rated for 220, 480 & 600 right out of the box, as are the control devices like overloads, contactors, control transformers, etc...
Its unfortunate us Canucks didn't get together with our American brothers in the beginning to set up a standard distribution and rule system but it is too late now and we have to deal with it when cross border shopping, while the rules are getting closer all the time the 2 power systems will always remain different...
Cheers,
Jon

danlb
05-24-2013, 03:15 PM
I have to chuckle at some of these posts. Especially the ones warning of deadly car batteries and phone lines.

I'm not going to bother trying to educate anyone, but I can assure you that millions of workers touch live, bare telephone wires every day with zero danger. I used to solder over 500 live connections per night, holding the wires and solder with bare hands. The phone lines only have 48 volts DC on them. Since it's DC the resistance from hand to hand is what limits the current.

At the moment the resistance from left hand to right is 3,126,000 ohms. To get current you divide volts by the resistance. The current from touching a 48 volt wire with two hands is thus .000015355 amps. You don't even notice that.

If it's AC, then it's a different issue. The impedance becomes the limiting factor. According to Wiki, the impedance of most people is around 2500 ohms at 48 volts. Obviously a lot more current will flow with AC.

The picture changes if you puncture the skin and get into the more conductive tissue underneath. By the time you have live wires embedded in your skin you have other problems.


A domestic power supply voltage (110 or 230 V), 50 or 60 Hz alternating current (AC) through the chest for a fraction of a second may induce ventricular fibrillation at currents as low as 30 mA.[3] With direct current (DC), 300 to 500 mA is required.[4] If the current has a direct pathway to the heart (e.g., via a cardiac catheter or other kind of electrode), a much lower current of less than 1 mA (AC or DC) can cause fibrillation.



Thanks for the chuckles guys!

Dan

Black_Moons
05-24-2013, 03:50 PM
At the moment the resistance from left hand to right is 3,126,000 ohms. To get current you divide volts by the resistance. The current from touching a 48 volt wire with two hands is thus .000015355 amps. You don't even notice that.

If it's AC, then it's a different issue. The impedance becomes the limiting factor. According to Wiki, the impedance of most people is around 2500 ohms at 48 volts. Obviously a lot more current will flow with AC.

The picture changes if you puncture the skin and get into the more conductive tissue underneath. By the time you have live wires embedded in your skin you have other problems.
Thanks for the chuckles guys!

Dan

So wrong...
First off, thats 'At the moment', Add some sweat and watch it drop to 20kohm or so. 0.0024A (2.4mA) at 48v, Not fatal sure, but trust me, with wet hands you can start to feel 24v DC, 48v is rather unplesent with wet hands, not very noticable with bone dry hands.

Also, Phone lines *ring* at 90V *AC*, thats DEFINATELY unplesent, reguardless if your hands are wet or not.

Next, Impedance is *NEVER* lower then DC resistance. It can't be. Impedance is reactance at a given freqency added to DC resistance. Humans are not huge coils of wire and hence they have near 0 reactance at 60hz, Hence our impedance is going to be near the exact same as resistance at 60hz.

The *internal* resistance of the human body is around 2500ohms (or less) once you puncture the skin, Meaning that if you are stupid enough to stab each hand with a phone line, even 48v, now at 0.019A (19mA), can be fatal (Typically, 15mA across the chest is considered 'fatal' or at least a good chance of being 'fatal')

Re: Jon Heron:
I am not even going to touch the '120v is (less/more) safe then (some other high voltage)' issue, But I will say your logic is flawed if you think comparing the number of deaths caused from *BILLIONS* of 120v appliances and connections operated in large by the untrained public, Often repaired and worked on by untrained unlisenced indivuals, to the number of deaths caused from millions of 600v industrial services only operated on by trained electicians, means anything at all. Its like saying cars are less safe then dragsters because more people die in cars every year, dispite the fact cars outnumber dragsters a million to one.

Evan
05-24-2013, 04:42 PM
I can commonly feel a slight tingle from car batteries when my hands are sweaty but there is no danger of passing enough current to cause a problem. Try a 9 volt battery on your tongue. I'm sure most people have. Make it 50 vdc to find what it can do in the right (wrong) circumstances. No thank you.

Also, when a telephone rings the voltage is around 90 to 110 vac at varying low frequencies. That will get your attention.

danlb
05-24-2013, 05:10 PM
Also, when a telephone rings the voltage is around 90 to 110 vac at varying low frequencies. That will get your attention.

As a telephone company worker I'd get hit by ringing current once or twice a day. The terminals were less than 1/2 inch apart so the shock was localized to that small patch of skin and felt like a bee sting. The pain subsides immediately, leaving only the memory and a sheen of sweat to ensure that you will feel the next one.

Ringing signal is typically 20 Hz. I don't recall any instance where i experienced any sort of muscle contractions as a result of ringing current.

Are there any credible accounts of people being seriously harmed by a ringing telephone? I could not find any.

Dan

quasi
05-24-2013, 08:27 PM
I do not recall ever seeing a motor rated for 208, 480 and 600 volts?

ulav8r
05-24-2013, 10:07 PM
The first time my dad had me help him install some wiring, we worked it hot. We were adding several outlets to a circuit. Got a couple of tingles doing that. The last time I got a shock, my wedding band got caught on a corner on the inside edge of an old fuse box at the same time as it contacted a live spot. I don't know/remember if it was a wire, screw or what.

Dad was a power company lineman and was used to working around hot wires.

WhatTheFlux!
05-24-2013, 10:11 PM
Hey thank you for answering the original question. This thread has turned into QUITE the education regarding electric power and safety.

A.K. Boomer
05-24-2013, 10:57 PM
The last time I got a shock, my wedding band got caught on a corner on the inside edge of an old fuse box at the same time as it contacted a live spot. .

I worked for a guy who was a body/shop repairman and he got his stuck between the positive 12 volt and ground of the car frame, turned it red hot within seconds - left one hell of a scar says he almost lost the finger...


anyone hear the tale of the death row inmate who refused water for days and days before getting the electric chair and survived the first initial shock or two? not saying it's true - just saying I heard about it and I live in a prison town so take it for what it's worth...

J. Randall
05-25-2013, 05:18 AM
Used to inspect on new pipeline construction, and we quite frequently cut someones phone line. I always carried the stuff to splice them back. One day I was down in a pretty damp bell hole, and had one end of the line in each hand just when someone called, I got a dose of that 90 volts or better AC and it hurt like the dickens. Tingles don't bother me, I just grab on to the plug wire on lawn equipment to check for fire.
James

Jaakko Fagerlund
05-25-2013, 05:56 AM
Are there any credible accounts of people being seriously harmed by a ringing telephone?
Back in my days in the Finnish Defence Forces, we tied up the rigged up phone line to the big toes of a sleeping private who should have been awake monitoring for calls. When the phone call came in, he surely was awake.

Though, it wasn't him who was hurt badly but the guys who attached the wires after he found out :D

loose nut
05-25-2013, 10:40 AM
When we take over and make Canada our 52nd state (right after Puerto Rico)

That's a joke right?

When your debt finally cause the total collapse of the US we will buy up the northern states for fractions of a penny on the dollar, Mexico can have the southern states back.:cool:

Jon Heron
05-25-2013, 02:34 PM
Re: Jon Heron:
I am not even going to touch the '120v is (less/more) safe then (some other high voltage)' issue, But I will say your logic is flawed if you think comparing the number of deaths caused from *BILLIONS* of 120v appliances and connections operated in large by the untrained public, Often repaired and worked on by untrained unlisenced indivuals, to the number of deaths caused from millions of 600v industrial services only operated on by trained electicians, means anything at all. Its like saying cars are less safe then dragsters because more people die in cars every year, dispite the fact cars outnumber dragsters a million to one.
I gave none of my logic for you to consider flawed Black moons, I gave you some statistical information and a personal experience, as well as the problem with 120V being nasty for getting hung up on... You can make your own conclusions with your logic, flawed or not...

I do not recall ever seeing a motor rated for 208, 480 and 600 volts?
Quasi, I have seen many, they make them every day. Not 208 but 220 - 600, you can likely special order one for 208 but they would not be so common, 120/208 3 phase systems are used more in commercial applications then for industrial...
Cheers,
Jon

The Artful Bodger
05-25-2013, 03:39 PM
120/208V is (or was) used with aircraft.

MaxHeadRoom
05-25-2013, 04:38 PM
120/208V is (or was) used with aircraft.

Also at 400Hz?
Max.

The Artful Bodger
05-25-2013, 05:07 PM
Yes, 400Hz 120/208V.

Duffy
05-25-2013, 11:21 PM
And to confuse the issue some more, torpedo power supplies ran at 2300Hz 120/208V. At least the Mk 44 did.

jdunmyer
05-27-2013, 07:24 PM
Back in the late 1960's, I was a checkout tech on relay control systems. They used dozens (sometimes MANY dozens) of relays & stepper switches, mostly 120 volts. My boss at the time told me that if I didn't get bit once a day, I probably wasn't working hard enough. He wasn't far off...

Some places in the US use 550/575 volt motors, I know of one where my wife worked for years, Sun Oil Refinery in Toledo, OH. She once scored 2 old Lincoln motor/generator welders, one was 440 volts, the other 550. When I got 480 volt 3-phase power in my barn, I dragged them out to see if I could make one work. Turned out that the 440-volt stator was burned out, so I did some parts swapping and ended up with a working welder, rated at 550 volts. Convinced myself that 480 was pretty close to 550 volts and it would probably work as long as I didn't weld much above 350 amps or so. It's been OK so far, since about 1980, so I'm hopeful that it'll last.