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Topic: Surge diverters Generators and Power Factor. (Read 514 times) previous topic - next topic
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Surge diverters Generators and Power Factor.

Yahoo Message Number: 74185
Does anyone have any idea how load power factor affects current levels ? Bob 06 intrigue 12047

Hi All

I note with interest your chats about generators and power factor. And your discussion of Watts.
I would just like to point out that Voltage X Amperes does not always equal Watts If the load being supplied is purely resistive then V x A = Watts. By resistive I mean a heater or the like.
However if the load being supplied has a motor in it as does an Air conditioner then Watts is calculated by multiplying Volts by Amps by the cosine of the out of phase angle between them known as a power factor. This can be in the region of 0.5 on some motors.
Now not wanting to get too technical here but suffice to say be aware that an aircon wanting 3000W to run will need more than 25A to run at 120V If the motor is such that it runs at a power factor of 0.5 then the Amperage will be 50A.
If the motor is such that it runs at a power factor of 0.8 then the Amperage will be 31.25A.
However capacitors installed in the air conditioners may help somewhat with poor their poor power factor. Always read the name plate and follow manufacturers directions.
It is always safer to use the Amperage needed and not Wattage if the power factor of the load is not known.
When buying a generator to match to a load ensure you use the VA or kVA rating and not Watts then you can be sure it will not overload.
Regards
Peter J