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Re: [microhydro] Re: voltage drop

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  • mika@etfi.org
    Dear Shabab, Have you considered using DC - transmission system. With such a small power the simple AC/DC and furthermore DC/AC converters are relatively
    Message 1 of 11 , May 1, 2008
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      Dear Shabab,

      Have you considered using DC - transmission system. With such a small power
      the simple AC/DC and furthermore DC/AC converters are relatively cheap.
      There are many benefits with DC transmission compared to AC. First of all
      the capacity of cable is much bigger ie less resistive heat losses allowing
      either longer distances or smaller cables. Then, depending on soil
      conditions it might be even possible to use ground as return wire - meaning
      that only one wire could be enough. And last, but definately not least, the
      quality of power is made in DC/AC converter that can be located close to
      consumption point.

      Regards,

      Mika




      Quoting shabab wahid <shababwahid@...>:

      > dear sir,
      > thank you . you are most welcome in the discussion.
      > its a small pelton turbine(single jet) and the means of regulating
      > the flow is spear/nozzle arrangement manually.
      > i know the distribution line is too lengthy but i have few choices
      > as choosing heavier conductors would be costly.
      > i am planning to use compact flouracent bulbs.Do these work on low
      > voltage.i would also like to know if i can use voltage stabilizers
      > some where in the middle of the distribution system.
      > will it work
      > regards
      > shabab
      >
      > nando <nando37@...> wrote:
      > Shabab:
      >
      > Though you are asking Joe, I am putting my foot in my mouth.
      >
      > #10 gauge is 1 ohm/1000 feet, so for 14000 feet, the resistance will
      > be 14 ohms and at 5 amps the voltage is 70 volts drop which is 32 %
      > losses and not the 5 % maximum for good operating service.
      >
      > How are you regulating the generated AC to see if a current feedback
      > can be included to vary the output voltage to follow the current
      > load to keep the voltage stable at the load end. -- though a bit
      > problematic !!
      >
      > Nando
      >
      > ----- Original Message -----
      > From: shabab wahid
      > To: microhydro@yahoogroups.com
      > Sent: Monday, April 28, 2008 8:41 PM
      > Subject: Re: [microhydro] Re: voltage drop
      >
      > hi joe
      > the generation voltage is 220 volts ac 50 hz.one way distance is
      > 7000 ft what would be the voltage drop and power loss if we use 10
      > AWG copper conductor.
      > regards
      > shabab
      > Joseph Hartvigsen <jjh@...> wrote:
      > Hi Shabab,
      > This is a long wire run, 14000 feet of conductor for the round trip.
      > You didn't mention the voltage, but for 3000W at 5A that works out to
      > 600V. Normally a 5% voltage drop is allowed. That works out to a #6AWG
      > wire size which is rather costly for that length. For example, at
      > 1500V and 2A a #14 AWG wire would work. So, you'd have to consider the
      > cost and efficiency losses for transformers to boost the voltage, as
      > well as the wire insulation rating.
      >
      > Joe h-hydro.com
      >
      > --- In microhydro@yahoogroups.com, "shababwahid" <shababwahid@...> wrote:
      >>
      >> dear friends
      >> we are planning to install a 3 kw microhydro scheme .we are intending
      >> to use single phase generator.we are planning to use insulated copper
      >> conductor.The load is 5 amperes at the end at a distance of 7000 ft.
      >> what gauge (swg) of copper conductor is suitable
      >> please reply at your earliest.
      >> regards
      >> shabab
      >>
      >
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      >
      > [Non-text portions of this message have been removed]
      >
      >
      >
      >
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    • nando
      Mika: First: DC or AC the wire losses are the same, for this small system, Second: the conversion to AC becomes too expensive for small systems Third: Initial
      Message 2 of 11 , May 1, 2008
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        Mika:

        First: DC or AC the wire losses are the same, for this small system,

        Second: the conversion to AC becomes too expensive for small systems

        Third: Initial power generation AC wise is cheaper and no problems with AC conversion from a DC power source including greater efficiencies.

        Fourth : For small systems AC power transmission is easy to implement with transformer to reduce the wire losses and the cost of the wire if the distance is appreciable.

        Fifth: If proper considerations are in place the load at distance can be properly regulated.

        The basic problems in quite a few systems is that the builder is trying to use shortcuts in the system to reduce the investment costs -- maybe financial limitations -- which may cause undesirable systems conditions that may affect the operation and the power usage due to some wild "shortcuts" installations.

        Nando

        ----- Original Message -----
        From: mika@...
        To: microhydro@yahoogroups.com
        Sent: Thursday, May 01, 2008 8:49 AM
        Subject: Re: [microhydro] Re: voltage drop


        Dear Shabab,

        Have you considered using DC - transmission system. With such a small power
        the simple AC/DC and furthermore DC/AC converters are relatively cheap.
        There are many benefits with DC transmission compared to AC. First of all
        the capacity of cable is much bigger ie less resistive heat losses allowing
        either longer distances or smaller cables. Then, depending on soil
        conditions it might be even possible to use ground as return wire - meaning
        that only one wire could be enough. And last, but definately not least, the
        quality of power is made in DC/AC converter that can be located close to
        consumption point.

        Regards,

        Mika

        Quoting shabab wahid <shababwahid@...>:

        > dear sir,
        > thank you . you are most welcome in the discussion.
        > its a small pelton turbine(single jet) and the means of regulating
        > the flow is spear/nozzle arrangement manually.
        > i know the distribution line is too lengthy but i have few choices
        > as choosing heavier conductors would be costly.
        > i am planning to use compact flouracent bulbs.Do these work on low
        > voltage.i would also like to know if i can use voltage stabilizers
        > some where in the middle of the distribution system.
        > will it work
        > regards
        > shabab
        >
        > nando <nando37@...> wrote:
        > Shabab:
        >
        > Though you are asking Joe, I am putting my foot in my mouth.
        >
        > #10 gauge is 1 ohm/1000 feet, so for 14000 feet, the resistance will
        > be 14 ohms and at 5 amps the voltage is 70 volts drop which is 32 %
        > losses and not the 5 % maximum for good operating service.
        >
        > How are you regulating the generated AC to see if a current feedback
        > can be included to vary the output voltage to follow the current
        > load to keep the voltage stable at the load end. -- though a bit
        > problematic !!
        >
        > Nando
        >
        > ----- Original Message -----
        > From: shabab wahid
        > To: microhydro@yahoogroups.com
        > Sent: Monday, April 28, 2008 8:41 PM
        > Subject: Re: [microhydro] Re: voltage drop
        >
        > hi joe
        > the generation voltage is 220 volts ac 50 hz.one way distance is
        > 7000 ft what would be the voltage drop and power loss if we use 10
        > AWG copper conductor.
        > regards
        > shabab
        > Joseph Hartvigsen <jjh@...> wrote:
        > Hi Shabab,
        > This is a long wire run, 14000 feet of conductor for the round trip.
        > You didn't mention the voltage, but for 3000W at 5A that works out to
        > 600V. Normally a 5% voltage drop is allowed. That works out to a #6AWG
        > wire size which is rather costly for that length. For example, at
        > 1500V and 2A a #14 AWG wire would work. So, you'd have to consider the
        > cost and efficiency losses for transformers to boost the voltage, as
        > well as the wire insulation rating.
        >
        > Joe h-hydro.com
        >
        > --- In microhydro@yahoogroups.com, "shababwahid" <shababwahid@...> wrote:
        >>
        >> dear friends
        >> we are planning to install a 3 kw microhydro scheme .we are intending
        >> to use single phase generator.we are planning to use insulated copper
        >> conductor.The load is 5 amperes at the end at a distance of 7000 ft.
        >> what gauge (swg) of copper conductor is suitable
        >> please reply at your earliest.
        >> regards
        >> shabab
        >>
        >
        > Send instant messages to your online friends http://uk.messenger.yahoo.com
        >
        > [Non-text portions of this message have been removed]
        >
        > [Non-text portions of this message have been removed]
        >
        >
        >
        >
        >
        > Send instant messages to your online friends http://uk.messenger.yahoo.com
        >
        > [Non-text portions of this message have been removed]
        >
        >





        [Non-text portions of this message have been removed]
      • nando
        Shabab: Joe, many times, can not respond immediately because he may be traveling. Spear control implies that the system is quite stable load wise and you will
        Message 3 of 11 , May 1, 2008
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          Shabab:

          Joe, many times, can not respond immediately because he may be traveling.

          Spear control implies that the system is quite stable load wise and you will not have such conditions because the length of the transmission line which may generate too big voltage fluctuations.

          Even if you plan to use fluorescent lamps, the fluctuations can be higher enough to damage many of them.

          The best arrangement is to get transformers producing at least 2 or 3 KV to lower the wire losses to less than 3 -5 % and to reduce the wire cost.

          We have done small systems where the hydro has a transformer to raise the voltage at least 10 times ( what is available in your area) and secondaries transformers at different load areas that may be too far from the hydro placement.

          This way the over all system will be stable with less operational problems and better voltage regulation.

          The idea of using electronic stabilizer to maintain the voltage regulation at the load area, may work but the power losses may be higher .

          Electronic Stabilizer do require transformer for proper operation and in a sense you are paying close to the cost of two transformers to do the same job -- so go for the transformers, better solution and more stable.

          The experiments that we have made with such stabilizers showed us that the path to follow was to go for transformers.

          Nando


          ----- Original Message -----
          From: shabab wahid
          To: microhydro@yahoogroups.com
          Sent: Wednesday, April 30, 2008 8:41 PM
          Subject: Re: [microhydro] Re: voltage drop


          dear sir,
          thank you . you are most welcome in the discussion.
          its a small pelton turbine(single jet) and the means of regulating the flow is spear/nozzle arrangement manually.
          i know the distribution line is too lengthy but i have few choices as choosing heavier conductors would be costly.
          i am planning to use compact flouracent bulbs.Do these work on low voltage.i would also like to know if i can use voltage stabilizers some where in the middle of the distribution system.
          will it work
          regards
          shabab

          nando <nando37@...> wrote:
          Shabab:

          Though you are asking Joe, I am putting my foot in my mouth.

          #10 gauge is 1 ohm/1000 feet, so for 14000 feet, the resistance will be 14 ohms and at 5 amps the voltage is 70 volts drop which is 32 % losses and not the 5 % maximum for good operating service.

          How are you regulating the generated AC to see if a current feedback can be included to vary the output voltage to follow the current load to keep the voltage stable at the load end. -- though a bit problematic !!

          Nando

          ----- Original Message -----
          From: shabab wahid
          To: microhydro@yahoogroups.com
          Sent: Monday, April 28, 2008 8:41 PM
          Subject: Re: [microhydro] Re: voltage drop

          hi joe
          the generation voltage is 220 volts ac 50 hz.one way distance is 7000 ft what would be the voltage drop and power loss if we use 10 AWG copper conductor.
          regards
          shabab
          Joseph Hartvigsen <jjh@...> wrote:
          Hi Shabab,
          This is a long wire run, 14000 feet of conductor for the round trip.
          You didn't mention the voltage, but for 3000W at 5A that works out to
          600V. Normally a 5% voltage drop is allowed. That works out to a #6AWG
          wire size which is rather costly for that length. For example, at
          1500V and 2A a #14 AWG wire would work. So, you'd have to consider the
          cost and efficiency losses for transformers to boost the voltage, as
          well as the wire insulation rating.

          Joe h-hydro.com

          --- In microhydro@yahoogroups.com, "shababwahid" <shababwahid@...> wrote:
          >
          > dear friends
          > we are planning to install a 3 kw microhydro scheme .we are intending
          > to use single phase generator.we are planning to use insulated copper
          > conductor.The load is 5 amperes at the end at a distance of 7000 ft.
          > what gauge (swg) of copper conductor is suitable
          > please reply at your earliest.
          > regards
          > shabab
          >

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        • shabab wahid
          dear sir, thank you for your suggesstions. i want to know if the unit is of 5 kw then do we have 6kva transforner available in the market of the ratio {1:10)
          Message 4 of 11 , May 5, 2008
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            dear sir,
            thank you for your suggesstions. i want to know if the unit is of 5 kw then do we have 6kva transforner available in the market of the ratio {1:10) you suggested .
            regards
            shabab

            nando <nando37@...> wrote:
            Shabab:

            Joe, many times, can not respond immediately because he may be traveling.

            Spear control implies that the system is quite stable load wise and you will not have such conditions because the length of the transmission line which may generate too big voltage fluctuations.

            Even if you plan to use fluorescent lamps, the fluctuations can be higher enough to damage many of them.

            The best arrangement is to get transformers producing at least 2 or 3 KV to lower the wire losses to less than 3 -5 % and to reduce the wire cost.

            We have done small systems where the hydro has a transformer to raise the voltage at least 10 times ( what is available in your area) and secondaries transformers at different load areas that may be too far from the hydro placement.

            This way the over all system will be stable with less operational problems and better voltage regulation.

            The idea of using electronic stabilizer to maintain the voltage regulation at the load area, may work but the power losses may be higher .

            Electronic Stabilizer do require transformer for proper operation and in a sense you are paying close to the cost of two transformers to do the same job -- so go for the transformers, better solution and more stable.

            The experiments that we have made with such stabilizers showed us that the path to follow was to go for transformers.

            Nando

            ----- Original Message -----
            From: shabab wahid
            To: microhydro@yahoogroups.com
            Sent: Wednesday, April 30, 2008 8:41 PM
            Subject: Re: [microhydro] Re: voltage drop

            dear sir,
            thank you . you are most welcome in the discussion.
            its a small pelton turbine(single jet) and the means of regulating the flow is spear/nozzle arrangement manually.
            i know the distribution line is too lengthy but i have few choices as choosing heavier conductors would be costly.
            i am planning to use compact flouracent bulbs.Do these work on low voltage.i would also like to know if i can use voltage stabilizers some where in the middle of the distribution system.
            will it work
            regards
            shabab

            nando <nando37@...> wrote:
            Shabab:

            Though you are asking Joe, I am putting my foot in my mouth.

            #10 gauge is 1 ohm/1000 feet, so for 14000 feet, the resistance will be 14 ohms and at 5 amps the voltage is 70 volts drop which is 32 % losses and not the 5 % maximum for good operating service.

            How are you regulating the generated AC to see if a current feedback can be included to vary the output voltage to follow the current load to keep the voltage stable at the load end. -- though a bit problematic !!

            Nando

            ----- Original Message -----
            From: shabab wahid
            To: microhydro@yahoogroups.com
            Sent: Monday, April 28, 2008 8:41 PM
            Subject: Re: [microhydro] Re: voltage drop

            hi joe
            the generation voltage is 220 volts ac 50 hz.one way distance is 7000 ft what would be the voltage drop and power loss if we use 10 AWG copper conductor.
            regards
            shabab
            Joseph Hartvigsen <jjh@...> wrote:
            Hi Shabab,
            This is a long wire run, 14000 feet of conductor for the round trip.
            You didn't mention the voltage, but for 3000W at 5A that works out to
            600V. Normally a 5% voltage drop is allowed. That works out to a #6AWG
            wire size which is rather costly for that length. For example, at
            1500V and 2A a #14 AWG wire would work. So, you'd have to consider the
            cost and efficiency losses for transformers to boost the voltage, as
            well as the wire insulation rating.

            Joe h-hydro.com

            --- In microhydro@yahoogroups.com, "shababwahid" <shababwahid@...> wrote:
            >
            > dear friends
            > we are planning to install a 3 kw microhydro scheme .we are intending
            > to use single phase generator.we are planning to use insulated copper
            > conductor.The load is 5 amperes at the end at a distance of 7000 ft.
            > what gauge (swg) of copper conductor is suitable
            > please reply at your earliest.
            > regards
            > shabab
            >

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          • Nando
            SHABAB: The transformer capacity and voltage ratio needs to be found by you in the area where you are. Search with the electric company that supplies power
            Message 5 of 11 , May 6, 2008
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              SHABAB:

              The transformer capacity and voltage ratio needs to be found by you in the area where you are.

              Search with the electric company that supplies power nearby to see what can be found -- 6.5 to 7.5 KVA

              The transformer needs to be 1:10 to 1:20 and this ratio does not need to be precise.

              Also. they should be for external use if they are going to be placed on Posts to avoid human contact ( a necessity).

              Nando


              ----- Original Message -----
              From: shabab wahid
              To: microhydro@yahoogroups.com
              Sent: Monday, May 05, 2008 11:50 PM
              Subject: Re: [microhydro] Re: voltage drop


              dear sir,
              thank you for your suggesstions. i want to know if the unit is of 5 kw then do we have 6kva transforner available in the market of the ratio {1:10) you suggested .
              regards
              shabab

              nando <nando37@...> wrote:
              Shabab:

              Joe, many times, can not respond immediately because he may be traveling.

              Spear control implies that the system is quite stable load wise and you will not have such conditions because the length of the transmission line which may generate too big voltage fluctuations.

              Even if you plan to use fluorescent lamps, the fluctuations can be higher enough to damage many of them.

              The best arrangement is to get transformers producing at least 2 or 3 KV to lower the wire losses to less than 3 -5 % and to reduce the wire cost.

              We have done small systems where the hydro has a transformer to raise the voltage at least 10 times ( what is available in your area) and secondaries transformers at different load areas that may be too far from the hydro placement.

              This way the over all system will be stable with less operational problems and better voltage regulation.

              The idea of using electronic stabilizer to maintain the voltage regulation at the load area, may work but the power losses may be higher .

              Electronic Stabilizer do require transformer for proper operation and in a sense you are paying close to the cost of two transformers to do the same job -- so go for the transformers, better solution and more stable.

              The experiments that we have made with such stabilizers showed us that the path to follow was to go for transformers.

              Nando

              ----- Original Message -----
              From: shabab wahid
              To: microhydro@yahoogroups.com
              Sent: Wednesday, April 30, 2008 8:41 PM
              Subject: Re: [microhydro] Re: voltage drop

              dear sir,
              thank you . you are most welcome in the discussion.
              its a small pelton turbine(single jet) and the means of regulating the flow is spear/nozzle arrangement manually.
              i know the distribution line is too lengthy but i have few choices as choosing heavier conductors would be costly.
              i am planning to use compact flouracent bulbs.Do these work on low voltage.i would also like to know if i can use voltage stabilizers some where in the middle of the distribution system.
              will it work
              regards
              shabab

              nando <nando37@...> wrote:
              Shabab:

              Though you are asking Joe, I am putting my foot in my mouth.

              #10 gauge is 1 ohm/1000 feet, so for 14000 feet, the resistance will be 14 ohms and at 5 amps the voltage is 70 volts drop which is 32 % losses and not the 5 % maximum for good operating service.

              How are you regulating the generated AC to see if a current feedback can be included to vary the output voltage to follow the current load to keep the voltage stable at the load end. -- though a bit problematic !!

              Nando

              ----- Original Message -----
              From: shabab wahid
              To: microhydro@yahoogroups.com
              Sent: Monday, April 28, 2008 8:41 PM
              Subject: Re: [microhydro] Re: voltage drop

              hi joe
              the generation voltage is 220 volts ac 50 hz.one way distance is 7000 ft what would be the voltage drop and power loss if we use 10 AWG copper conductor.
              regards
              shabab
              Joseph Hartvigsen <jjh@...> wrote:
              Hi Shabab,
              This is a long wire run, 14000 feet of conductor for the round trip.
              You didn't mention the voltage, but for 3000W at 5A that works out to
              600V. Normally a 5% voltage drop is allowed. That works out to a #6AWG
              wire size which is rather costly for that length. For example, at
              1500V and 2A a #14 AWG wire would work. So, you'd have to consider the
              cost and efficiency losses for transformers to boost the voltage, as
              well as the wire insulation rating.

              Joe h-hydro.com

              --- In microhydro@yahoogroups.com, "shababwahid" <shababwahid@...> wrote:
              >
              > dear friends
              > we are planning to install a 3 kw microhydro scheme .we are intending
              > to use single phase generator.we are planning to use insulated copper
              > conductor.The load is 5 amperes at the end at a distance of 7000 ft.
              > what gauge (swg) of copper conductor is suitable
              > please reply at your earliest.
              > regards
              > shabab
              >

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