Announcement

Collapse
No announcement yet.

Ok CANADA, EXPLAIN this

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by philbur View Post
    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.

    Comment


    • #17
      Originally posted by bandsawguy View Post
      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 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...
      Last edited by A.K. Boomer; 05-23-2013, 10:55 AM.

      Comment


      • #18
        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.

        Comment


        • #19
          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"
          Last edited by A.K. Boomer; 05-23-2013, 11:46 AM.

          Comment


          • #20
            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.

            Comment


            • #21
              Originally posted by Stern View Post
              The required current to stop the heart is only around 10mA,

              You said it not me

              Comment


              • #22
                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

                Comment


                • #23
                  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...

                  Comment


                  • #24
                    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).
                    please visit my webpage:
                    http://motorworks88.webs.com/

                    Comment


                    • #25
                      Originally posted by WhatTheFlux! View Post
                      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!

                      Comment


                      • #26
                        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
                        OPEN EYES, OPEN EARS, OPEN MIND

                        THINK HARDER

                        BETTER TO HAVE TOOLS YOU DON'T NEED THAN TO NEED TOOLS YOU DON'T HAVE

                        MY NAME IS BRIAN AND I AM A TOOLOHOLIC

                        Comment


                        • #27
                          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

                          Comment


                          • #28
                            Originally posted by A.K. Boomer View Post
                            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.

                            Comment


                            • #29
                              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.
                              Free software for calculating bolt circles and similar: Click Here

                              Comment


                              • #30
                                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

                                Originally posted by Stern View Post
                                the killer is current, not voltage.

                                Comment

                                Working...
                                X