Can anyone help anwer this about PFC?

[imjune]

I've been reading all over about PFC but I still can't get the practical explanation for this. CMIIW Power Factor = Real Power/ Apparent Power.

Does this mean that a 1000 Watt PSU with 0.9 Power Factor is actually only able to supply 900 Watt?

Or does this mean that 1000 Watt PSU with 0.9 Power Factor, under full load is using 1111 VA?

Or is there another practical explanation?

Thank you

[Prodigy_Smit]

1 minute ago, imjune said:

Or does this mean that 1000 Watt PSU with 0.9 Power Factor, under full load is using 1111 VA?

This.

Also if you are trying to save money don't waste money on Power Factor Correctors. Electroboom made a great video on this.

 

[Ankerson]

3 hours ago, imjune said:

I've been reading all over about PFC but I still can't get the practical explanation for this. CMIIW Power Factor = Real Power/ Apparent Power.

Does this mean that a 1000 Watt PSU with 0.9 Power Factor is actually only able to supply 900 Watt?

Or does this mean that 1000 Watt PSU with 0.9 Power Factor, under full load is using 1111 VA?

Or is there another practical explanation?

Thank you

 

NO, that's not what it means.

 

A good quality PSU, say a 1000W PSU will supply 1000W of power as needed.

[akio123008]

On 1/20/2021 at 6:59 AM, imjune said:

1000 Watt PSU with 0.9 Power Factor, under full load is using 1111 VA?

In theory: exactly that.

 

In practice, there's also efficiency; say the efficiency is 90%, that means the power consumption is already 1111W, and then the power factor apparent power would be 1111/0.9 = 1234.4VA

 

But a power supply with active PSU can easily do 0.95+ so I generally wouldn't worry about it at all.

[imjune]

On 1/20/2021 at 1:02 PM, Prodigy_Smit said:

This.

Also if you are trying to save money don't waste money on Power Factor Correctors. Electroboom made a great video on this.

 

 

23 hours ago, Ankerson said:

 

NO, that's not what it means.

 

A good quality PSU, say a 1000W PSU will supply 1000W of power as needed.

 

11 hours ago, akio123008 said:

In theory: exactly that.

 

In practice, there's also efficiency; say the efficiency is 90%, that means the power consumption is already 1111W, and then the power factor would be 1111/0.9 = 1234.4VA

 

But a power supply with active PSU can easily do 0.95+ so I generally wouldn't worry about it at all.

Thank you all for the answer. Exactly what I need. 

 

[mariushm]

A good power supply will give components the amount of watts on the label. 

If all the voltage x current added together  equals 1000 watts, that means the power supply can give 1000 watts to components. 

 

In order to produce those various voltages, the power supply will convert the AC voltage to DC and then to lower voltages with a certain efficiency, in gold+ power supplies that's typically over 92-95% ... so if 1000 watts go to components, around 1100 watts are taken from AC main.

 

The power supply has a PFC circuit which raises the power factor to around 0.9+ , which means the apparent power "seen" by the power station is a bit more than that, maybe 1200-1300 watts. You don't pay for apparent power, only real power, so you'll pay for those 1100 watts

 

Probably said the same thing the guys above me said, just in other words. Not trying to "steal their thunder" or anything