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Power Density - Single or Three Phase?

Simon87
Hello all,


Quick question regarding initial load assessments using power densities.


Keeping my numbers simple, lets say we take a small power density of 20W/m2, over a GIA of 1000m2, this gives a max demand of 20kW. Now i have always taken this to be a single phase load, and so if the space is being served via a three phase power supply, would it be correct to split this 20kW across the three phases (assuming perfect balance across phases). i.e. the small power maximum demand for the space would be 6.7kW.


Any help would be appreciated.


Thanks in advance,


Simon.


Parents
  • 0
    What is the reqd MPR (kva)? 

    Any 3 phase equipment?


    MPR (kva) 35mm2 single phase Al split concentric/concentric 100 amp cut out max 100 amp fuse.

    1--------23


    MPR (kva) 35 mmsq2 three phase Al concentric 100 amp cut out max 100 amp fuse.

    24-------69


    These are small size services. For budding distribution engineers the rule of thumb for calculation is:

                                                           I=4xkva dividedx3

    So 3 phase, 4x69 dividedx3 = 92ampxphase. 

    These are balanced loads, on site measurements are different.

    So Mr Jewsbury is correct in saying the load is across 3 phases.

    Regards, UKPNZap

                                                               

Reply
  • 0
    What is the reqd MPR (kva)? 

    Any 3 phase equipment?


    MPR (kva) 35mm2 single phase Al split concentric/concentric 100 amp cut out max 100 amp fuse.

    1--------23


    MPR (kva) 35 mmsq2 three phase Al concentric 100 amp cut out max 100 amp fuse.

    24-------69


    These are small size services. For budding distribution engineers the rule of thumb for calculation is:

                                                           I=4xkva dividedx3

    So 3 phase, 4x69 dividedx3 = 92ampxphase. 

    These are balanced loads, on site measurements are different.

    So Mr Jewsbury is correct in saying the load is across 3 phases.

    Regards, UKPNZap

                                                               

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