"Power Factor Correction"?

I bought a replacement power supply unit from Dell for my Dimension 4500. It
was real easy. The Dell part number on my original PSU was 0N380, and the
Dell rep said she couldn't get that particular part so she substituted a
unit with Dell part number 2N333.

I looked up both part numbers on Dell's web site and their description is
the same, except for one difference: My original PSU was "non-Power Factor
Correction" and the replacement is "Power Factor Correction". What is the
difference?

Ted Zieglar

I looked up both part numbers on Dell's web site and their description is
the same, except for one difference: My original PSU was "non-Power Factor
Correction" and the replacement is "Power Factor Correction". What is the
difference?

In a non-related to power supplies type response, power factor correction
is sometimes applied to a "dirty" inductive load, where the electrical
effect of the load causes the phase angle to change which means the power
used is less effective, so relatively costs more to run (its been years
since I did any of this, so I might be wrong in my description)

Power factor correction is likely to be pretty minimal I would have
thought for a small power supply, but is not a bad thing in itself.

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Thanks, Colin.

Modem Ani

"Colin Wilson" wrote in message
t...
I looked up both part numbers on Dell's web site and their description
is
the same, except for one difference: My original PSU was "non-Power
Factor
Correction" and the replacement is "Power Factor Correction". What is
the
difference?

In a non-related to power supplies type response, power factor correction
is sometimes applied to a "dirty" inductive load, where the electrical
effect of the load causes the phase angle to change which means the power
used is less effective, so relatively costs more to run (its been years
since I did any of this, so I might be wrong in my description)

Power factor correction is likely to be pretty minimal I would have
thought for a small power supply, but is not a bad thing in itself.

--
Please add "[newsgroup]" in the subject of any personal replies via email
--- My new email address has "ngspamtrap" & @btinternet.com in it ;-) ---

Ted Zieglar wrote:
Thanks, Colin.

Ditto - seemed like some real info from someone who actually knows what
he's talking about (nice change of pace on this NG)!

On Thu, 31 Mar 2005 10:01:58 -0500, "Ted Zieglar"
wrote:

I bought a replacement power supply unit from Dell for my Dimension 4500. It
was real easy. The Dell part number on my original PSU was 0N380, and the
Dell rep said she couldn't get that particular part so she substituted a
unit with Dell part number 2N333.

I looked up both part numbers on Dell's web site and their description is
the same, except for one difference: My original PSU was "non-Power Factor
Correction" and the replacement is "Power Factor Correction". What is the
difference?

Ted Zieglar




Ted, just curious, what did it cost from Dell? I've also got a 4500
and may end up doing the same thing down the road.

In article , wrote:
I looked up both part numbers on Dell's web site and their description is
the same, except for one difference: My original PSU was "non-Power Factor
Correction" and the replacement is "Power Factor Correction". What is the
difference?

In a non-related to power supplies type response, power factor correction
is sometimes applied to a "dirty" inductive load, where the electrical
effect of the load causes the phase angle to change which means the power
used is less effective, so relatively costs more to run (its been years
since I did any of this, so I might be wrong in my description)

Power factor correction is likely to be pretty minimal I would have
thought for a small power supply, but is not a bad thing in itself.

Yeah. Last time I ran into this term was when trying to buy a welder!
Here in Oz PFC was/is mandatory for high inductance loads. Seems it
was/is possible to run your meter backwards here if you have such a
load commensurate with normal load in the absence of PFC. ;-)

Cheers, Phred.

--
LID

The power supply itself was $30 plus shipping. Dell automatically adds
next-day delivery ($16) since they presume that if you're ordering a power
supply you need it asap, but you can ask for a slower, less expensive method
if you like.

As long as I was going to replace my power supply, I thought I would go with
a fancier unit from a third party. Dell uses a proprietary power supply, but
there are ways to adapt a standard unit to fit the 4500. If you decide to go
this route, search the internet for the model number shown on the label
attached to your Dell PSU. (Don't confuse the model number with Dell's part
number, or the bar code number.) That provided links to several suppliers
with compatible units and adapters to make them work with your motherboard.

The thing is, these third party units cost twice what Dell was asking. And
Dell's PSU is guaranteed by Dell to work in my computer. So in the end I
went with Dell. If the replacement is like the original, then by the time
the replacement starts getting noisy it will be time to buy a new computer
anyway.

Ted Zieglar


Rob wrote in message ...
On Thu, 31 Mar 2005 10:01:58 -0500, "Ted Zieglar"
wrote:

I bought a replacement power supply unit from Dell for my Dimension 4500.
It
was real easy. The Dell part number on my original PSU was 0N380, and the
Dell rep said she couldn't get that particular part so she substituted a
unit with Dell part number 2N333.

I looked up both part numbers on Dell's web site and their description is
the same, except for one difference: My original PSU was "non-Power
Factor
Correction" and the replacement is "Power Factor Correction". What is the
difference?

Ted Zieglar




Ted, just curious, what did it cost from Dell? I've also got a 4500
and may end up doing the same thing down the road.

From the replies I have received, and subsequent searching on the web, it
occurs to me that power factor correction is a concept over my head, but
that it's a good thing to have on a power supply (or at least, not a bad
thing.) I can deal with that.

Ted Zieglar

"Phred" wrote in message
...
In article ,
wrote:
I looked up both part numbers on Dell's web site and their description
is
the same, except for one difference: My original PSU was "non-Power
Factor
Correction" and the replacement is "Power Factor Correction". What is
the
difference?

In a non-related to power supplies type response, power factor correction
is sometimes applied to a "dirty" inductive load, where the electrical
effect of the load causes the phase angle to change which means the power
used is less effective, so relatively costs more to run (its been years
since I did any of this, so I might be wrong in my description)

Power factor correction is likely to be pretty minimal I would have
thought for a small power supply, but is not a bad thing in itself.

Yeah. Last time I ran into this term was when trying to buy a welder!
Here in Oz PFC was/is mandatory for high inductance loads. Seems it
was/is possible to run your meter backwards here if you have such a
load commensurate with normal load in the absence of PFC. ;-)

Cheers, Phred.

--
LID

Agreed in general, but a bit of a quibble on the mention of
increased cost to run.

IIRC the change of phase angle means that the power consumed is not used
effectively, so as an example, although a "dirty load" may draw 10 amps
in operation, it may only be effectively "using" 8 amps - PFC reduces the
phase angle so the "lost" 2 amps is reduced.

Reducing the phase angle by use of PFC means you reduce the "lost"
current, so you're not paying for the power you're unable to use by
virtue of the "dirty" load.

Picture two sine waves superimposed - the closer the peaks to each other
the better the efficiency of the load. A purely resistive load doesn't
affect the "phase angle" (the "offset" between the two sine waves).

A "dirty" (inductive) load forces the two sine waves to part company, and
the bigger the offset between the two, the less efficient the use of
power.

Back to pure speculation here as its been close to 20 years since I did
any of this :-} but I think the point at which the sine waves cross
signifies the "actual" use you get out of the power, while the peak
signifies what you're actually having to pay for it.

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"Colin Wilson" wrote in message
t...
Agreed in general, but a bit of a quibble on the mention of
increased cost to run.

IIRC the change of phase angle means that the power consumed is not used
effectively, so as an example, although a "dirty load" may draw 10 amps
in operation, it may only be effectively "using" 8 amps - PFC reduces the
phase angle so the "lost" 2 amps is reduced.

Reducing the phase angle by use of PFC means you reduce the "lost"
current, so you're not paying for the power you're unable to use by
virtue of the "dirty" load.

Picture two sine waves superimposed - the closer the peaks to each other
the better the efficiency of the load. A purely resistive load doesn't
affect the "phase angle" (the "offset" between the two sine waves).

A "dirty" (inductive) load forces the two sine waves to part company, and
the bigger the offset between the two, the less efficient the use of
power.

Back to pure speculation here as its been close to 20 years since I did
any of this :-} but I think the point at which the sine waves cross
signifies the "actual" use you get out of the power, while the peak
signifies what you're actually having to pay for it.

--
Please add "[newsgroup]" in the subject of any personal replies via email
--- My new email address has "ngspamtrap" & @btinternet.com in it ;-) ---

Notwithstanding all the above (generally correct), the reason PFC was
introduced is regulatory requirements, centered mostly in Europe. It
really ended up burdening many electronic eqpt purchasers (like us) with
additional cost, just to sate the fact that state run power suppliers prefer
to have their load PF as close to 1 as possible, thereby reducing the need
for installing higher current capacity transmission eqpt.

Not really germane, but that's the "bottom line".