Hi! Hom many Amps are necessary to run an average computer including, printer
fax, scanner in concert--all average items.Amps and watts when applicable.

Hello and thank you for your question.

According to this website, you should budget 4 amps for the computer
and 1.8 amps for the monitor.
http://www.chaminade.org/MIS/EnergyTechnology.htm

If you're in the U.S., your wiring delivers 110 volts.
Since amps x volt = watts, that's (4 + 1.8) * 110 = 638 watts

A laserprinter draws about 465 watts (at 110 volts, that's 4.2 amps)
http://www.globalprinter.com/printers/4100.asp

An inkjet printer only 12 watts (.1 amp)
http://www.book.uci.edu/bookstore/computer/Hardware/printers&scanners/photoprinter_pdf/hpPhotoSmart230xi.pdf

An all-in-one printer/fax about 220 watts (2 amps)
http://www.microcenter.com/single_product_results.phtml?product_id=171653

And a scanner as little as 2.5 watts (.03 amps) or up to 20 watts (.2 amps)
http://www.epinions.com/content_36016197252
http://www.hardwarezone.com/articles/view.php?cid=13&id=292&pg=

So the total is as much as 12 amps, or 1,320 watts.  Since most
household circuits are 15 or 20 amps, they should run OK together.

Search terms used
Dell desktop watts
HP laserjet watts
HP inkjet watts
scanner watts

Thanks again for bringing us your question



Sincerely,
Google Answers Researcher
Richard-ga

Hi  smack-ga,

   In addition to the information provided by richard-ga, you might
find the following information useful:

-In order to run the equipments successfully in concert, you also
need to consider the peak current requirements(this should equal or be less
than the surge current capability of your generator/portable power supply 
or the circuit breaker rating of the outlet), mostly required during the
initial start of the equipment, and during specific stages of operation
(eg. a laser printer on standby might not require the power mentioned,
except during operation and computer waking up from standby might produce
a sudden surge).

-An ideal way to estimate the true power would be to use a watt meter
(of kill-a-watt type)connected to the equipment, to figure out the exact 
needs for your computer/peripherals.  You could also use a circuit breaker
tracer to confirm if nearby outlets belong to different breakers/circuits.

-Operating equipments connected to an outlet close to the max. rating,
could be detremental(might cause unnecessary voltage drops, and even trip
the circuit breaker at times).  It is always better to have sufficient
margin(about 25%) above the maximum power requirements. It might be better
to share the equipments between multiple circuits to be on the safer side.

-Modern power supplies in the computers are very much tolerant to load induced
voltage fluctuations, but it may not be the case with peripherals such as
laser printer or the scanner(eventhough it consumes too little a power). If
you do not have a choice other than to run your equipments close to the
maximum rating of your outlet, you could benefit by the use of a variac(auto
transformer) based voltage stabilizer.

Regards
ldavinci-ga

I believe the answer is wrong. Bear in mind none of these equipment
uses the 110 mains AC voltage directly. More likely, the computer has
a PSU(Power Supply Unit) that transforms the mains voltage to
something like (12V DC,6V DC, -6V DC, -12V DC).
Assuming the 4Amps consumption for the computer is correct(I haven't
checked it), you will be drawing 12Vx4A~=48Watts. At mains voltage,
the 4A will be only a fraction. The 6V terminals of the computer will
most likely be used by the cooling fans and draw minimal current.
  Similar calculations will yeld the correct Watts for the remaining
equipment. One good estimate for the max power drained by the
equipment is look at the specifications that are usually in the
transformers, or near in the back, where you connect the power cable.
Ex: if the transformer has the following label(this example is from a
laptop transformer):
INPUT: AC 100-240V
OUTPUT: DC 20V 3.5A
it means the output power will be at maximum 70W(20V*3.5A), and a lot
less current AC mains voltage.

Hope it helps..

The comment
 
 From: tautology-ga on 04 Jun 2004 04:11 PDT 
  
saying "I believe the answer is wrong" is confused.

Today's desktop computer has typical power supply 300W

In US, at AC (wall outlet level ) that would be around 3A, 
as answer correctly says
       at DC level, 5V to 12V that would be many more Amps, up to 20A or 30A,
depending on the internal operating voltage.

Comment is incorrectly combining Amps at the input (primary) with volts
at the output, (socondary) of the power supply
 and so underestimates power by factor of 10.

do not forget that a computer power supply is not 100% efficient - its
DC output may be rated at 300W but to get this power its AC power draw
is higher. If the power supply is 60% efficient then its AC power draw
is 300/0.6

For a typical high powered system (whats in the case only!) you are
looking at between 120 and 200 watts DC when it is running at full
load. This translates to between 200 and 333 watts of AC power....and
back to the original question that is between 2 and 3 amps. (at
110V...less at 240V!!)