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Thread: Getting #250 Al onto 1/0 Lugs

  1. #11
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    Wouldn't want to show this to someone and simply say "hook it up just like the picture shows".


    JAP>

  2. #12
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    Quote Originally Posted by jap View Post
    That picture is extremely deceiving to say the least.

    JAP>
    How so?
    "Electricity is really just organized lightning." George Carlin


    Derek

  3. #13
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    Quote Originally Posted by kwired View Post
    One problem he likely runs into though is that there is not enough bending space for a 250 conductor in a meter center compartment that is only rated for 100-125 amps.
    Do the bending space rules apply to the install or to the product?
    Bob

  4. #14
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    Quote Originally Posted by jumper View Post
    How so?
    at first glance it is not real clear just where the wires are going. It fooled me for a second too.
    Bob

  5. #15
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    Quote Originally Posted by jumper View Post
    How so?
    Look at the Polaris connector in the center.
    Although its not, at a quick glance, it looks like it is.

    JAP>

  6. #16
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    Quote Originally Posted by petersonra View Post
    Do the bending space rules apply to the install or to the product?
    Kind of sort of both IMO.

    100/125 amp meter sockets, circuit breaker enclosures typically only have lugs that accept about 2/0 maximum conductor as well as have bending space not much more then is needed for 2/0 conductor. 200/225 amp devices often accept about 300 kcmil max conductor and have no more bending space then is needed for 300 also.

  7. #17
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    75 degree conductors vs 90 degree.

    Quote Originally Posted by JFletcher View Post
    Also, you realize that if you use Polaris connectors on both ends and 90*C wire, you are permitted to use the 90*C table for ampacity for the wire between the 2 (but 75*C for the wire from connector to meter and breaker). I know you oversized for VD reasons, just throwing that out there.
    Can you provide a little more information about this? I don't understand the difference between the ampacity of the long wires and the short wires.

  8. #18
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    Quote Originally Posted by Greg1707 View Post
    Can you provide a little more information about this? I don't understand the difference between the ampacity of the long wires and the short wires.
    It's not about the wire.
    It's about the temperature rating of the terminals.

    Most Polaris connector terminals are rated at 90d C so you can use the 90d C column when determining the amperage of the long wires in between 2 Polaris connectors.

    Breakers or meters generally have lugs only rated at 75d C so the short wire from the Polaris connector to the meter or the short wire from the Polaris conductor to the breaker terminals needs to be figured in the 75d column.

    At least that's what I think he's trying to say.

    JAP>

  9. #19
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    Quote Originally Posted by jap View Post
    It's not about the wire.
    It's about the temperature rating of the terminals.

    Most Polaris connector terminals are rated at 90d C so you can use the 90d C column when determining the amperage of the long wires in between 2 Polaris connectors.

    Breakers or meters generally have lugs only rated at 75d C so the short wire from the Polaris connector to the meter or the short wire from the Polaris conductor to the breaker terminals needs to be figured in the 75d column.

    At least that's what I think he's trying to say.

    JAP>
    Exactly what I was getting at. And if you happen to need a feeder with an ampacity right on the edge of wire sizes, like 425A, it's the difference between using 500MCM copper (430A @ 90*C) and 750 MCM copper (475A @ 75*C - 600 is good to 420A). or parallel sets of 3/0 vs 4/0. On a long run, that will add up quickly, especially if you also have to upsize the conduit to hold the larger wires rated at 75*C vs 90*C.
    Electricians do it until it Hertz!

  10. #20
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    Quote Originally Posted by JFletcher View Post
    Exactly what I was getting at. And if you happen to need a feeder with an ampacity right on the edge of wire sizes, like 425A, it's the difference between using 500MCM copper (430A @ 90*C) and 750 MCM copper (475A @ 75*C - 600 is good to 420A). or parallel sets of 3/0 vs 4/0. On a long run, that will add up quickly, especially if you also have to upsize the conduit to hold the larger wires rated at 75*C vs 90*C.
    That's good thinking.

    JAP>

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