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how to upgrade electricity supply to Phase 3

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  1. #11

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    Quote Originally Posted by hongkonggirl:
    Hello,
    My friend has bought a new property on HK Island. She then found that the electricity supply is Phase 1. She would like to upgrade to phase 3. Upon enquiry the management informed her that all the electricity available for uprage to phase 3 has already been allocated.
    Is there anyone else she can contact for the upgrade? Like, for example, HK electric? Is it possible for her to carry out the upgrade privately, and not through the buildings management?
    no.....the building probably has one or more 2500 amp TPN three phase risers - there is tee at each floor split to serve the CLP/HKE meters, seems these are single phase meters in this case.

    anyone can apply for more power by making application to CLP/HKE with load calculations (It has nothing to do with the building management) if the utility agree the tenant has to complete the installation and submit application for connection of the meter.

    A new 3 three phase cable and containment from the existing meter room to the unit is likely to pass through the common area , it may fit inside the existing containment (existing trunking system) if not new containment will be needed and that needs approval from building owner/management, fire services dept. and perhaps even from BD.

    the short answer is nobody knows
    - does the meter room have space for new larger meter?
    - does the busbar chamber have enough space for large capacity breakers?
    - does the containment have spare capacity to house the new cables?
    - is there enough space in the unit to dump the existing single phase board and fit a new three phase board?

    pay an electrician day rate to check, it is not something that can be easily answered on a forum.
    shri likes this.

  2. #12

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    Thank you all. It is actually an old building. (Built around 1976/77) but with all the facilities. Gas water heaters, lift etc. Very useful information from all of you.
    Appreciate it.


  3. #13

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    Thank you JAherbert, for the clarification. I will pass the information to my friend.


  4. #14

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    Quote Originally Posted by hongkonggirl:
    Thank you all. It is actually an old building. (Built around 1976/77) but with all the facilities. Gas water heaters, lift etc. Very useful information from all of you.
    Appreciate it.
    If gas water heater, then this doesnt need 3 phase power. Only instantaneous electric water heaters could benefit from 3 phase, but even then you can get single phase ones as well and in a country like HK that doesnt get so cold is often enough, unless you like really hot showers.

  5. #15

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    Quote Originally Posted by bdw:
    If gas water heater, then this doesnt need 3 phase power. Only instantaneous electric water heaters could benefit from 3 phase, but even then you can get single phase ones as well and in a country like HK that doesnt get so cold is often enough, unless you like really hot showers.
    Gas Boilers should be banned..... Dirty old tech

    Great when fitted after a few years pollution makers.
    JAherbert likes this.

  6. #16

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    Quote Originally Posted by bdw:
    If gas water heater, then this doesnt need 3 phase power. Only instantaneous electric water heaters could benefit from 3 phase, but even then you can get single phase ones as well and in a country like HK that doesnt get so cold is often enough, unless you like really hot showers.
    yes you can buy, but older flats only have 63A single phase supply, for the whole unit

    a standard instantaneous electric water heater is 18kw, that demands 75 amp (single phase running current)
    a 18kw, three phase service draws much lower current, about 43 amps for the same power.

  7. #17

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    Oct 2016
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    We have old school three-phase supply in the apartment we just moved into... three consumer units with red / yellow / blue stickers on!

    But them we have also have mammoth (three-phase) airconditioner in the sitting room!!


  8. #18

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    Quote Originally Posted by JAherbert:
    yes you can buy, but older flats only have 63A single phase supply, for the whole unit

    a standard instantaneous electric water heater is 18kw, that demands 75 amp (single phase running current)
    a 18kw, three phase service draws much lower current, about 43 amps for the same power.
    75amp, that would be some serious juice!

    For everyone else , that's a 16mm cable required to handle that load (the diameter of the copper not including the insulation).

    Your normal household applications have copper wire of 1.5mm or 2.5mm diameter.

  9. #19

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    Thank you all for your extremely valuable contributions. Highly appreciated.


  10. #20

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    Quote Originally Posted by bdw:
    If gas water heater, then this doesnt need 3 phase power. Only instantaneous electric water heaters could benefit from 3 phase, but even then you can get single phase ones as well and in a country like HK that doesnt get so cold is often enough, unless you like really hot showers.
    I did try a instantaneous water heater in my 1 phase flat. The shop warned against it, but I decided to try my luck.

    Summer is obviously fine. But when it is most needed in Winter, I could only get it to lukewarm water before tripping the fuse. When you are in the cold 10 degree HK with no heating, having a shower in warmish 30 degree water is no fun either especially if there is a risk the fuse will trip if you use more water and you are left with cold water or having to run naked in the cold to the fuse box.
    bdw likes this.