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3 phase loads

3 phase loads

3 phase loads

(OP)
I am intending to connect 9 2kw metal halide lights so that they are balanced over the 3 phases. The supply voltage is 400v between phases. This will mean that the load is balanced with 3 lights connected in paralell across each phase. This will bean that there is 6kw connected between phases. I want to know how to calculate the current taken from each phase of the supply. I do not know the power factor of the lights. Any help would be greatly appreciated.
Thanks in advance.

RE: 3 phase loads

Its simple.

If the load is evenly divided between the three phases, the total load is 18kW (3*6kW).

For a balanced three phase load, Line Current I= (18kW/p.f.)/[(SQRT (3))*400] in each line.

where kw/p.f.= kvA.

Or you can say voltage per phase is 400/sqrt 3 =230V

Current for each phase = kva per phase/voltage per phase
=(6kW/p.f.)/230. Either shall result in the same current value.

RE: 3 phase loads

(OP)
Thanks rbulsara, that's exactly what I was looking for

RE: 3 phase loads

One correction:

I forgot the factor of 1000. Multiply kVA*1000 to get VA.

(or use voltages in kV).

RE: 3 phase loads

Suggestion: The current may need to be increased a little bit since there will probably be ballasts that will increase the 2kW to some higher value depending on which type of ballast is applied.

RE: 3 phase loads

(OP)
Thanks jbartos,
I got the power factor rating of the ballast from the lighting manufacturer and I have sorter out the problem.
Thanks to all for your helpful replies.

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