VA converted to KW

[sunelectricbx]

How do you convert VA to KW?
For example Gen Lighting = 4,235 VA, how many KW
or Appliance load = 80,800 VA, how many KW
or total load = 130,600 VA, how many KW

[ October 07, 2005, 02:56 PM: Message edited by: sunelectricbx ]

 

[charlie b]

Re: VA converted to KW

If there are no motors, just divide by 1000 (to account for the "K" part of "KW"). If there are motors, then you need to break them out separately.

If you know (from separate sources of information) what the overall power factor of the system is, then the general equation is KW equals VA times power factor, then divide by 1000.

 

[bphgravity]

Re: VA converted to KW

Divide the VA by 1000 to find KVA.

KVA does not equal KW, but interchanging the terms for the purposes of a load calculation is not a big deal.

 

[rcwilson]

Re: VA converted to KW

VA = Volts x Amps = Watts/power factor

1 Kilowatt = 1 KW = 1000 Watts

Watts/1000 = kW

(VA x power factor)/1000 = kWatts, or

Watts /(1000 x power factor) = kVA.

@ 1.0 pf:

Watts/(1000 x 1.0) = kW.

For unity (1.0) power factor loads like heating and incandescent lamps, 1 VA = 1 watt.

For motors, lamps with ballasts, transformers, and other things that need magnetic fields to work correctly, the power factor is less than 1.0.

A rule of thumb is loads like these run about 0.8-0.85 power factor. So:

kVA x 0.80 = kW or
kVA = kW/0.80

VA x 0.8 (1000) = kW.

 

[rattus]

Re: VA converted to KW

Just what everyone needs to know:

Electrical units of measure may be combined with multipliers to make the units easier to handle.

The common multipliers are:

kilo = 1,000 = 10^3
mega = 1,000,000 = 10^6
giga = 1,000,000,000 = 10^9
tera = 1,000,000,000,000 = 10^12

milli = 1/1,000 = 10^-3
micro = 1/1,000,000 = 10^-6
nano = 1/1,000,000,000 = 10^-9
pico = 1/1,000,000,000,000 = 10^-12

Examples are kilovolts, milliamps, millivolts, millihenrys, kilohms, megohms, microfarads, picofarads, etc.