On Sun, 19 Jul 2009 16:19:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

wrote:

Possibly because some laser printers have 1000 watt fusing elements
and most home UPS units can't provide that much power?

They go out of their way to hide it. A friend of mine moved here with a 120
volt industrial strength HP laser printer. The specs said 325 watts, the
current draw was listed as 8 amps max on the last page of the manual.

Only 8 amps? HP is usually fairly good about supplying power
consumption specs. For example, for the HP LJ 3200 all in one, see:
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=bpl08239&locale=en_US&taskId =101&prodSeriesId=24354&prodTypeId=18972#A8
Inrush Current: (Duration: significantly 1 second)
Model A (120V): 23 A peak (20 deg C, from cold start)
Model AB (240V): 40 A peak (20 deg C, from cold start)

With a 23A inrush current, the UPS is gonna go into shutdown, blow a
fuse, or somehow complain. (I haven't tried it).

What I find amusing is that in order to get an Energy Start rating,
the printer must reduce average consumption to below 50% of normal
power consumption. This is usually done with a power save shut down
and an "instant on" feature. However, to get reasonable startup time,
the initial inrush current is really high.

My current small Samsung printer never actually says what it draws, but the
web page and manual made a big point about it drawing 6 watts in standby. Since
we print around 5 times a week, the standby current matters more than the
max draw, but I would not want to plug it into a UPS.

My clamp-on amps guesser has a peak hold function. I'll try it out on
some of my LaserJet printers in the office and see what it shows.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558