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    #31
    Originally posted by Fulthrotl View Post
    i'd talk to programmers instead. but, do whatever works for you.

    i know an independent programmer who is $1k a day, plus expenses.
    he is booked weeks ahead. nets about $220k a year. flies all over the
    country doing this stuff. laptop and a airline carry on bag.
    Shoot, I am limited to Lutron stuff and can still pick up small contracts and make an easy buck.
    [COLOR="blue"]"Electricity is really just organized lightning." George Carlin


    Derek[/COLOR]

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      #32
      Originally posted by Fulthrotl View Post
      i know an independent programmer who is $1k a day, plus expenses.
      Where do I sign up?

      (seriously, it's a line of work I'm willing to try and wrangling bad user interfaces is all in a day's work)

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        #33
        Originally posted by ActionDave View Post
        So what. The point is you can do it.
        NEC has a section on low voltage lighting.

        Is there a reason these need CAT 5/6 instead of simple two wire supply?

        Sparky's not knowing how to program a lighting control? I don't expect to get into very much if any of that before I retire. Of course I don't plan to move to CA either.

        Put occupancy sensors in restrooms in a small town church, happened to be church I attend. I tried to talk them out of them, some were concerned about lights getting left on occasionally and the wasted energy/money. I told them there isn't that much for lights, and that if they only get left on occasionally the sensors will cost more then they will ever save. They still have times when the sensors won't turn the lights off and have spent more on service calls then they ever saved
        I live for today, I'm just a day behind.

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          #34
          Originally posted by kwired View Post
          NEC has a section on low voltage lighting.

          Is there a reason these need CAT 5/6 instead of simple two wire supply?

          Sparky's not knowing how to program a lighting control? I don't expect to get into very much if any of that before I retire. Of course I don't plan to move to CA either.

          Put occupancy sensors in restrooms in a small town church, happened to be church I attend. I tried to talk them out of them, some were concerned about lights getting left on occasionally and the wasted energy/money. I told them there isn't that much for lights, and that if they only get left on occasionally the sensors will cost more then they will ever save. They still have times when the sensors won't turn the lights off and have spent more on service calls then they ever saved
          Yeah I get that frequently, "we want to save money." After a bunch of timers/phtotcells/occupancy sensors and labor.......
          Ethan Brush - East West Electric. NY, WA. MA

          "You can't generalize"

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            #35
            Originally posted by kwired View Post
            NEC has a section on low voltage lighting.

            Is there a reason these need CAT 5/6 instead of simple two wire supply?
            PoE is not just running 12V over a pair of wires. Depending on the standard it uses 2 or 4 pairs. It uses a much higher voltage and both ends of the circuit work together to regulate voltage and current. The newer PoE standards allow for 70+ watts per port at 100 meters (328'). Using standard 2-wire cable to run 12v from a remote driver to remote LED lighting will require some very large cable over that kind of distance.
            Curt Swartz
            Electrical Contractor

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              #36
              With PoE you still have the usual ethernet data on the cable also.

              Aren't the conductors actually a smaller gauge with CAT 7?

              -Hal

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                #37
                Originally posted by curt swartz View Post
                PoE is not just running 12V over a pair of wires. Depending on the standard it uses 2 or 4 pairs. It uses a much higher voltage and both ends of the circuit work together to regulate voltage and current. The newer PoE standards allow for 70+ watts per port at 100 meters (328'). Using standard 2-wire cable to run 12v from a remote driver to remote LED lighting will require some very large cable over that kind of distance.
                I'll admit to not knowing a lot about PoE, but figured power was likely on just one pair.

                I don't see how you could get 70 watts over 100 meters on such small conductors without getting into "power circuit" ratings rather than class 2/3/ communications circuit ratings, unless maybe you did utilize all four pairs for power.
                I live for today, I'm just a day behind.

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                  #38
                  Originally posted by kwired View Post
                  I'll admit to not knowing a lot about PoE, but figured power was likely on just one pair.

                  I don't see how you could get 70 watts over 100 meters on such small conductors without getting into "power circuit" ratings rather than class 2/3/ communications circuit ratings, unless maybe you did utilize all four pairs for power.
                  They use two pair for data and the usually spare two pair for the power, usually. Putting power on the data pairs can cause too many problems with errors in data.

                  Of course, many of my old installations could not use this technique as we used the extra two pairs for telephones and intercoms..lol...
                  Student of electrical codes. Please Take others advice first.

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                    #39
                    POE DC voltage will cost much less in KW than converting AC from power company...

                    POE DC voltage will cost much less in KW than converting AC from power company...


                    Originally posted by KaBoom! View Post
                    I don’t see it...

                    As lights get more efficient, we are able to daisy chain more and more on each 120 or 277v circuit, which makes wiring easy and straight forward. Who wants thousands of extra runs of network cable to run and terminate?

                    Any of the benefits of having the lights connected to the network can also be had using currently wireless technology. My niece was so happy to show me how she can control the brightness and color of her bedroom light with her iPhone

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                      #40
                      Originally posted by Michael Hockenberry View Post
                      POE DC voltage will cost much less in KW than converting AC from power company...
                      And just where, pray tell, does the PoE -supplying switch get its power? Still gotta plug that switch into an AC receptacle...



                      SceneryDriver

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                        #41
                        Originally posted by SceneryDriver View Post
                        And just where, pray tell, does the PoE -supplying switch get its power? Still gotta plug that switch into an AC receptacle...



                        SceneryDriver
                        True, plus it will also have to be stepped down an additional time from 480 to 120 volt to feed the POE supply.

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                          #42
                          [QUOTE=SceneryDriver;1941900]And just where, pray tell, does the PoE -supplying switch get its power? Still gotta plug that switch into an AC receptacle...



                          It depends upon the actual applications and voltages but there are more and more converters for the poe applications to feed in the power. They make rack mounted, din rail mounted and wall mounted power transformers that can be hoooked up to supply quite a few different wattages... you also have transformers that make 24 volt center tapped so you in effect have the 24/12 volt options and they are starting to use an AC option for up to 36 volts.. so you have 24 and 36 vAC rather than volt DC... UL and BS registered along with EC registered..
                          seen a bunch of the options in my latest Rexel UK catalogue
                          SceneryDriver
                          Student of electrical codes. Please Take others advice first.

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                            #43
                            Originally posted by SceneryDriver View Post
                            And just where, pray tell, does the PoE -supplying switch get its power? Still gotta plug that switch into an AC receptacle...



                            SceneryDriver
                            I have POE switches that are DC powered. My telemetry cabinets are all DC devices. A AC DC 24 v power supply goes to a DC UPS, it charges a 12 VDC battery, in a power outage the DC ups converts 12 into 24 volts. I use a european battey that is rated at 10 years. I ran the telemetry panel on an 500 VA UPS - 3 hours on the DC ups it went 3 days
                            Moderator-Washington State
                            Ancora Imparo

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                              #44
                              There are multiple POE standards.

                              Ad-hoc or poor-man's uses the two unused pairs in 100baseT; voltage varies based on the power supply. Note that gigabit Ethernet uses all 4 pairs for data so this won't work.

                              True POE passes the power between two data pairs with the power fed to the center tap of the data isolation transformer on one end and picked up from the transformer on the other end. Voltage is 48v nominal though it can drop down to 37v at the far end. Current standards allow up to 50w depending on the standard; it looks like there's a new standard in the works for 100w

                              /mike

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                                #45
                                Whats the life span of a POE switch? And aren't they expensive?

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