NetKev wrote:
I got a multi-function laser printer for my home office. It replaced
an old laser printer that I had. This new printer causes the lights
to dim in the whole house when I print. While it prints, the lights
rhythmicly dim. This stops once the printer goes to sleep. My old
printer never did that. I ended up buying a new laser printer (for
unrelated reasons) and it does the same thing(if not worse).
I tried plugging it into different outlets without a difference. This
latest printer(Dell 1815dn) pulls 450 watts while printing. Here's
the spec sheet if you're interested:
http://www.dell.com/downloads/global...ron/1815dn.pdf
Anyways, this bugs the heck out of me and my wife. Especially when my
wife prints out large pdfs while I'm reading 
I read about this
phenomenon on the group and know that it's common...
This house we're renting was built in the 1950s and so I'm sure it
doesn't have the greatest electrical service.
But my question is how to fix it. Since we're renting I don't want to
make any drastic electrical system changes(cant actually). I was
thinking a UPS would work or maybe a power conditioner since I'm
assuming that the draw from the printing is so high that the rest of
the appliances are being starved. If a UPS were in the mix to provide
this extra power then the rest of the appliances wouldn't have a
problem.
If my solution theory is correct, any idea what size UPS I will need?
I'm hoping I don't have to spend a lot of money for it but who knows.
Thanks for your help/suggestions/pointers
-Kevin
It's pretty safe to say that a UPS isn't a good solution for a couple of
reasons, IMO. One, IF the UPS is a decent one then yes, it may minimze some
of the effect BUT you'll then have the UPS kicking in/out every time the
surge happens.
A UPS does NOT run off the battery unless/until power goes away. Then it
opens the AC line and the battery in it provides power to an inverter that
provides the 120 ac for you. So the battery isn't really relevant.
A UPS does watch the voltage levels (usually programmable). So, if the
dimming doesn't cause the voltage to bo below the UPS' "trip" voltage, the
UPS will do nothing.
IMO the actual problem is more likely incorrect wire gauge or loading. You
said plugging into different outlets made no difference, but then you said
the refrigerator, etc., doesn't make the lights dim? Did you try the
outlets the fridge, etc. is plugged into? With thge fridge or whatever
unplugged, of course.
If, when you plugged into a different outlet, that outlet wasn't on a
different fuse/breaker, then one would expect the results to be the same.
But if it's a different one, then it's possible the results may be more
acceptable.
Note that it only takes a few volts change to create noticeable light
outputs from incandescent bulbs. I have flourexcents in my computer room,
so I never see any of that dimming here or anywhere else in the house since
the outlets here are the only ones served by that breaker; plus the
lights/outlets are on different breakers.
Most likely, I'm going to guess that outlets/lights are all on the same
fuse/breaker whre you're plugging in the printer; and that's causing the
noticeable dimming flukes. Look into trying to separate them.
One mo Pinter specs do not give surge currents; they only spec the
current needed to keep the machine running at maximum speed. Like motors,
printers can have quite heavy surge currents when the diffuser heater comes
on.
And one more yet: a fuse/breaker, say a 20A one, should only have to
provide a maximum of 16 amps or less at any given time. AFter the 80%
point, voltage drops are incurred and may add to the dimming perceptions.
HTH
Pop`