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Cable question

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  • 29-07-2015 5:18pm
    #1
    Papa_Bear
    Registered Users Posts: 202 ✭✭


    What kind of cables are these?

    They have an armour made of aluminium. The one on the right looks alot like 2.5sq NYMJ and the one on the left is the same armour but is 1.5sq 4 core.

    The PE is in contact with the armour on both cables.

    Is the black one on the left 3ph and if so what would use 1.5sq 3ph. If not then what is it used for?

    Cheers

    356705.jpg


Comments

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    #2
    dolittle
    Registered Users Posts: 706 ✭✭✭dolittle


    could be high tension cable
    any chance of a csa?


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    #3
    red sean
    Registered Users Posts: 2,917 ✭✭✭red sean


    Looks like NHYRUZY or NHYBUY. Replaced by NYMJ.


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    #4
    Calahonda52
    Registered Users Posts: 12,471 ✭✭✭✭Calahonda52


    Three phase is much more efficient than single phase for the following reason

    1P: Watts = Volts by Amps
    3P: watts = 1.732 by volts by amps for resistive loads
    So 1P is normally 240 volts phase to neutral
    3P is 400 volts phase to neutral so for the same watts, the amps is 1.732 by (400/240) = 2.88 times less so cable size much smaller

    “I can’t pay my staff or mortgage with instagram likes”.



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    #5
    Bruthal
    Closed Accounts Posts: 13,422 ✭✭✭✭Bruthal


    Calahonda52 wrote: »
    Three phase is much more efficient than single phase for the following reason

    1P: Watts = Volts by Amps
    3P: watts = 1.732 by volts by amps for resistive loads
    So 1P is normally 240 volts phase to neutral
    3P is 400 volts phase to neutral so for the same watts, the amps is 1.732 by (400/240) = 2.88 times less so cable size much smaller
    The main thing that makes 3 phase more efficient for transmission at 400v is that a single neutral does the 3 lines. So less conductor material needed for the same supplied wattage. The higher voltage aspect being more efficient is true regardless of being single or 3 phase.


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    #6
    Papa_Bear
    Registered Users Posts: 202 ✭✭Papa_Bear


    Ok so it looks like nhyruzy cable with a zinc armour. Is that a PVC sheath on the black cable?

    I've got 13m of this obsolete stuff so my question now is; is it possible to use the black 4 core cable as ~3sq mm 1ph in say, a shed by combining the conductors into 2 pairs and heatshrink with blue and brown tubing and use the pair of bare conductors as PE?

    And if so is there a way to gland it/does it need glanding? what's the best way to remove the armour without cutting the insulation on the conductors?

    Thanks for your help.


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    #7
    [Deleted User]
    Posts: 5,238 ✭✭✭ [Deleted User]


    DC is even more efficient for transmission.
    The Chinese are running 500kVDC from the Three Gorges Damn.


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    #8
    ted1
    Registered Users Posts: 23,548 ✭✭✭✭ted1


    Sir Liamalot wrote: »
    DC is even more efficient for transmission.
    The Chinese are running 500kVDC from the Three Gorges Damn.

    Sure closer to home the EWIC is 400KV DC.


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    #9
    2011
    Moderators, Home & Garden Moderators, Technology & Internet Moderators, Regional East Moderators Posts: 12,595 Mod ✭✭✭✭2011


    Sir Liamalot wrote: »
    DC is even more efficient for transmission.
    The Chinese are running 500kVDC from the Three Gorges Damn.

    You don't have to go as far a China.

    The Moyle inter-connector provides a HVDC links Northern Ireland and Scotland through submarine cables running between converter stations at Ballycronan More in Islandmagee.

    Here is an interesting link on HVDC.
    Calahonda52 wrote: »
    Three phase is much more efficient than single phase for the following reason

    1P: Watts = Volts by Amps
    3P: watts = 1.732 by volts by amps for resistive loads
    So 1P is normally 240 volts phase to neutral
    3P is 400 volts phase to neutral so for the same watts, the amps is 1.732 by (400/240) = 2.88 times less so cable size much smaller

    There are many advantages that three phase have over single phase, saving a bit of copper would be very low on the list for most people :)


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