Power - Reactive Power

[Sparky2003]

Hi All - Hope you can help.
I have 2 Transport Refrigeration Units.

Unit 1 measures as follows:
Kw: 6.59
Kva: 8.11
Kvar: 4.77
PF: 0.81

Unit 2 measures as follows:
Kw: 5.28
Kva: 8.05
Kvar: 6.09
PF: 0.66

I need to advise which unit will heat cables less, or more and why. The customer in question has no power factor correction.

 

[waross]

I assume the units are at the same voltage. Heating is almost directly dependent on current. KVA is Current times voltage divided by 1000. If the voltage is equal, the unit with the higher KVA will have the higher current and so the higher heating.
yours

 

[LionelHutz]

If these units are the same voltage then the units are both drawing the same kVA which means they're drawing the same current so they would both heat the cables equally. Well, you're within a few % of each other here. If you did add capacitors you could lower the kVA of unit 2 more (lower pf means more correction is possible). So, after adding capacitors unit 1 would heat the cables more.

If these units are different voltages then the lower voltage unit would draw more current which would heat the cables more.

 

[jraef]

Cable size matters a lot as well. We are assuming that they are equal here.

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