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Load Calculations for 400v single phase floodlighting

seansasta
Hi Folks

Could someone please advise if my calculations below are correct? I'm calculating total load on a 3 phase 400v system for a floodlighting load consisting of 36 No 400v single phase ("2-phase") Luminaires. I thought my calc's were correct then I read some other posts online which used 3 phase formula (as if the stated lighting load was 3 phase) which left me with enough doubt in my calc's to seek some expert advice from you guys...

Supply: 3ph/400V

Load: 36No Philips OPTIVISION MVP507 1xMHN-LA2000W/400V/842 WB/60, with a stated load of 2123 W each, equally divided across the 3 phases, (I have assumed a Pf of 0.9 for the ballasts).

I have treated these as single phase loads, therefore...

I total = (2123*36)/(400*0.9) = 212.3A; divided equally across 3 phases = 71 A (70.77) line current

Therefore, (Assuming I used the correct calculations above) total 3 phase power in KW = ((400*1.732*0.9*71)/1000) = 44.27 KW


Any confirmations or corrections would be greatly appreciated.


Thanks

Parents
  • 0
    Yes, there are limits on cable length between lamp and ballast, but these are generous for lamps with internal ignitors. Details from the manufacturers of the equipment.

    Yes voltage drop between lamp and control gear needs to be allowed for. Note this current will be greater than the external circuit current since it will have a poor power factor. The power factor capacitors will be near the ballasts, and the current between lamp and ballast thereby not corrected.


    Voltage drop can sometimes be compensated for by selecting a tapping on the ballast that is lower than the actual voltage at the origin of the installation. Remember though that this represents an ongoing energy waste.
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  • 0
    Yes, there are limits on cable length between lamp and ballast, but these are generous for lamps with internal ignitors. Details from the manufacturers of the equipment.

    Yes voltage drop between lamp and control gear needs to be allowed for. Note this current will be greater than the external circuit current since it will have a poor power factor. The power factor capacitors will be near the ballasts, and the current between lamp and ballast thereby not corrected.


    Voltage drop can sometimes be compensated for by selecting a tapping on the ballast that is lower than the actual voltage at the origin of the installation. Remember though that this represents an ongoing energy waste.
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