Turn off laser printer with power strip?

[Gary Vocks]

I'm wondering if there are any negative effects on a color laser printer
from using a power strip to turn the printer on and off. I can't find
anything in the product documentation but I thought that people here might
know. I've been told that turning the power off to an inkjet without
turning the printer off via it's own switch is a no-no but I was wondering
if that holds true for a color laser. TIA

Gary

 

[Tony]

I'm wondering if there are any negative effects on a color laser printer
from using a power strip to turn the printer on and off. I can't find
anything in the product documentation but I thought that people here might
know. I've been told that turning the power off to an inkjet without
turning the printer off via it's own switch is a no-no but I was wondering
if that holds true for a color laser. TIA

Gary

Generally the answer is that no harm will be done to a Laser since the power
switch on a Laser invariably simply removes all power from the printer unlike
most inkjets where the power switch initiates an orderly close down and does
not actually remove power completely.
There may be exceptions however, although I am not aware of even one, what is
the printer?
Tony

 

[John Smith]

When you turn off the power switch on some laser printers, the internal fan
may continue to run for a short time to cool down the interior (if you've
been printing recently). I know that's true with HP Color LaserJets. If
you turn off the printer at a power strip, the fan loses its power too so
the fan can't do its job.

Likewise, when you turn off the power switch of an ink jet printer, before
completely shutting down the print head parks itself to the side and rests
on a material that keeps the ink nozzles from being exposed to air and
drying out. If you turn off the printer at a power strip, the print head
just stays wherever it was in the middle of the carriage.

You wrote "power strip," which is not the same thing as a surge protector.
Strictly speaking, a power strip is just an extension cord with multiple
outlets and doesn't contain any electronics. It's generally not a good idea
to power laser printers (or any other devices that draw large amounts of
current, such as space heaters, coffee pots, toasters, electric drills,
etc.) through a surge protector because they interfere with the surge
protection capability.

 

[Fred McKenzie]

I'm wondering if there are any negative effects on a color laser printer
from using a power strip to turn the printer on and off. I can't find
anything in the product documentation but I thought that people here might
know. I've been told that turning the power off to an inkjet without
turning the printer off via it's own switch is a no-no but I was wondering
if that holds true for a color laser. TIA

Gary-

I agree with Tony, at least for the printer's I'm familiar with.

Suppose the printer were in the middle of some operation, whether printing
or calibration. Killing it should be no different than opening the
printer while power is off and changing some internal part.

Some gears may be partially rotated as a result, but the power-up sequence
should recalibrate everything back to a nominal configuration. There is
always the possibility of a power failure, and the printer should be able
to cope with that.

If you're not convinced, at least be sure the printer is in a quiescent
mode when you kill the power.

Fred

 

[w_tom]

Power strip is a surge protector without those internal $0.10 parts.
Both power strip and power strip surge protector connect that laser
printer directly to AC mains. Remove those $0.10 parts from a power
strip protector and install those parts inside a plug. When that plug
is plugged into a power strip, then the power strip is electrically
same as a power strip surge protector. Those parts - inside the power
strip or inside an attached plug - make no difference to how a laser
printer connects to AC mains.

It's generally not a good idea to power laser printers through a surge
protector because they interfere with the surge protection capability.

I will love to see this poster prove that one. Yes, that is an open
challenge. What is a power strip surge protector? Assuming it has an
essential 15 amp circuit breaker, then that surge protector is
electrically equivalent to a power strip ... as long as voltage never
exceeds its let-through voltage rating ... 330 volts. That's right.
That $25 surge protector does nothing as long as AC voltage does not
exceed the let-through voltage. That $23 protector is electrically
same as the $3 power strip when 120 volt AC does not exceed those 300
volts. This idea that high current devices 'interfere' is classic junk
science reasoning - complete with no reasons 'why' and no numbers.

Turn off laser printer power either using its power switch, using a
power strip, or using a wall switch. It's all the same and not
destructive to the laser printer.

 

[George E. Cawthon]

When you turn off the power switch on some laser printers, the internal fan
may continue to run for a short time to cool down the interior (if you've
been printing recently). I know that's true with HP Color LaserJets. If
you turn off the printer at a power strip, the fan loses its power too so
the fan can't do its job.

Likewise, when you turn off the power switch of an ink jet printer, before
completely shutting down the print head parks itself to the side and rests
on a material that keeps the ink nozzles from being exposed to air and
drying out. If you turn off the printer at a power strip, the print head
just stays wherever it was in the middle of the carriage.

You wrote "power strip," which is not the same thing as a surge protector.
Strictly speaking, a power strip is just an extension cord with multiple
outlets and doesn't contain any electronics. It's generally not a good idea
to power laser printers (or any other devices that draw large amounts of
current, such as space heaters, coffee pots, toasters, electric drills,
etc.) through a surge protector because they interfere with the surge
protection capability.

Huh? I don't think you have any support for that
statement. Large power consumers may overload the
capacity of the surge protector and trip the
breaker, turning off ever other appliance hooked
to the surge protector. That would be the main
reason for not using high current devices. The
surge protection isn't going to be affected.

 

[Tony]

Surge protectors are considered to be a cause of fuser error messages for some
laser printers. See http://www.advancedlaser.net/errorcode/error_50.htm for one
side of this debate. I am not going to get involved with the debate here
because neither side can win, but be aware that there IS a debate and I have
seen situations where bypassing a surge protector eliminates 50.X fuser errors.
The original post was about a power strip however which is a very different
beast and there is no evidence that these cause problems.
Tony

 

[John Smith]

I'm not an engineer; I should have prefaced my post with "From what I
understand..." Nevertheless, here are some links that support my
understanding that it's unwise to use a surge protector with a laser
printer.

Laser printer powerup can cause a brownout at the computer:
http://www.dummies.com/WileyCDA/DummiesArticle/id-2270.html
Laser printer powerup can fry a surge protector:
http://www.digital-photography.org/digital_graphics_studio_reviews/Best_UPS_surge_protectors.html
"Never plug a laser printer into a surge protector":
http://www.compamerica.com/userguide/
Laser printer can overload the surge protector:
http://www.dansdata.com/gz039.htm
Surge protector can reduce voltage to laser printers, causing errors:
http://www.pcnetmiami.com/
It is not recommended to power any laser printer through a surge protector:
http://www.serviceworks.com/sw-rlpq3.html

Admittedly, I also found web sites that recommend connecting a surge
protector to a laser printer, so maybe it comes down to personal preference.
My original intent was to say that a laser printer may adversely affect the
overall operation of the surge protector, including its surge protection
capability, but what I wrote instead implies that only the voltage spike
suppression is affected. Apologies are extended for not writing clearly.

Personally, I prefer to use my surge protectors on "clean" electronics. I
plug appliances, motors, and heating devices including laser printers
directly into the wall outlet, ideally on a separate circuit from my
computer. I don't want to purposely inject electrical noise into the device
whose purpose is to keep noise from the systems I'm trying to protect.

 

[George E. Cawthon]

I was going to reply without reading your
reference then decided, "What the hell."
Summaries follow:
1. printers need separate circuits to protect the
computer from brownouts.
2. Article about UPS not surge protectors
3. Instructions for a novice, and says never plug
a printer into a surge protector but doesn't say why.
4. Just a rant about surge protectors in general.
5. About trouble shooting problems, so plug
printer into the wall (to bypass a possible
problem with the surge protector)
6. Says don't put printer on a surge protector or
powerbar because of high current draw when printer
is turned on. (Means that the breaker in the
surge protector will flip off.)

Note that none of these have anything to do with a
printer damaging a surge protector.

 

[John Smith]

A surge protector also offers EMI/RFI filtering. Why purposely inject
trouble directly into your safety device?

I disagree with you that turning off a laser printer at its power switch, a
power strip, or a wall switch are all the same. Many laser printers (for
example, the HP Color LaserJet 4500) contain an internal fan that continues
to run for five minutes or so after the power is switched off if the printer
has recently been printing. If you turn the printer off at a wall switch or
power strip or disconnect the power cord, the fan stops running instantly
and the heat remains inside the printer. Sure, the heat will seep out
eventually and your printer won't die right away, but if you always let the
printer bake in its own heat your printer may only last five years instead
of ten (my estimates). Many products have cooling fans that continue to run
for awhile after the device is turned off. Car radiator electric fans and
overhead projector fans immediately come to mind.

 

[Gary Vocks]

Thanks for the replies on this. It's a Minolta QMS that doesn't get used
every day. Since, because of the location of the machine, I have to be a
contortionist to reach the On/Off switch I've tended to leave it on 24/7.
I'm sure that this is a big waste of energy so I'd like to figure a
practical way to turn it on and off. Moving the machine is not an option.
I'd be using a heavy-duty power strip, not a surge protector, plugged into a
wall outlet with the printer plugged into it. I wouldn't be turning it off
immediately after printing something so all the innards would have a chance
to settle down before I killed the power to it. Again, thanks for all the
replies.

Gary Vocks
www.under-1-roof.com

 

[John Smith]

Can you set the Minolta to go into power saving mode after a period of
inactivity?

 

[Gary Vocks]

It's my understanding that even in "sleep" or "standby" mode most electrical
devices still consume a significant amount of power. Please feel free to
correct me on this if I'm wrong.

Gary Vocks
www.under-1-roof.com

 

[Bob]

A surge protector also offers EMI/RFI filtering. Why purposely inject
trouble directly into your safety device?

It does? Not the ones I've seen. How can a surge protector possibly
do that? Look inside one and get back to me.

BTW - you might as well skip plugging the laser into a surge protector
as they do little to prevent common surges anyway (too small) and
just divert larger ones it into something else that will get fried as
an alternative. My guess is that Karma will make sure the most
expensive device gets fried Remember the law of conservation of
energy - it has to go somewhere - ask an engineer where it ends up
(Hint - it's not neatly diverted to the ground circuit).

You can get some utility from a UPS as it can maintain a steady
voltage to your equipment all the time... what most people mistakenly
think a surge protector does.

BTW - If you're thinking "yeah... but if lightening strikes I'm all
set with my protector" think again. Ask a power engineer about that
too when you have a chance. Unless you install a premises protection
device with a ground plate bigger than you ever realized you need, it
ain't gonna happen.

 

[Colin Brough]

BTW - you might as well skip plugging the laser into a surge protector
as they do little to prevent common surges anyway (too small) and
just divert larger ones it into something else that will get fried as
an alternative. My guess is that Karma will make sure the most
expensive device gets fried Remember the law of conservation of
energy - it has to go somewhere - ask an engineer where it ends up
(Hint - it's not neatly diverted to the ground circuit).

(I don't have the expertise to contribute to this directly.)

However, why then do the surge protectors sold in the UK (where I am)
often come with £10,000 or whatever protected equipment cover - "if
you get a spike and your equipment behind this surge protector is
damaged we'll buy you a new one". Are the manufacturers banking on
no-one taking them up on it?

Cheers

Colin

 

[Paul Walker]

Gary -

I'm not familiar with your printer. I do own a color laser printer.
Some thoughts/comments ...

1) I'd recommend consulting the owner's manual or asking the printer
manufacturer about this. They know the printer, and they're the ones
you will be arguing with regarding the warranty if it breaks.

2) My printer's owner's manual says to not use a power strip.

3) There may be more than fans that need power after the printer is
turned off. For example, my printer has a "bias transfer roller" that
extends when the printer is ready. If I pull the power cord instead of
using the off switch, it may not be able to retract the roller, due to
losss of power to operate the motor that retracts the roller. The
manufacturer wants it retracted when the printer is not ready.

4) Printers may use quite a bit less power when "asleep". My printer
is rated at 45 watts in power saver mode and 220 watts when ready.

I don't know details about your printer. If it were like mine, I
wouldn't use a power strip to cycle the power.

Paul

 

[w_tom]

A surge protector also offers EMI/RFI filtering. Why purposely inject
trouble directly into your safety device?

EMI/RFI filtering in power strip protectors is just another example
of junk science. Promoted without numbers in order to deceive. In
reality, a power strip protector does nothing useful for a consumer.
However, because it is so grossly overpriced, a power strip protector
vastly enriches its manufacturer. A manufacturer who conveniently
forgets to mention the most critical component for protection - earth
ground. Why mention missing earth ground when being honest will only
destroy those profits? Same with the EMI/RFI filter. Another myth
promoted by junk science reasoning - without numbers.

Meanwhile your logic is that if a fan in a printer or a car runs
after power off, then if fan does not run, damage will result.
Nonsense. Spin that only a politician could love. Does the laser
printer or car get hotter when powered off? Of course not. If a fan
does not spin, the laser printer and car still cool - just slower.

If removing power from a laser printer was so destructive, then the
laser printer would have warning IN BIG LETTERS in the owner's manual.

Makes no difference whether power is removed by printer switch, power
strip, or wall switch.

 

[Gary Tait]

I am going to say this.
I had a laser printer (older B&W) plugged into a power strip, with no
problems. I also have some older inkjets with a mains power switch, rather
than a soft off (they parked when done printing),

 

[Joel Kolstad]

It's my understanding that even in "sleep" or "standby" mode most electrical
devices still consume a significant amount of power. Please feel free to
correct me on this if I'm wrong.

Most machines are EPA Energy Star complaint these days; for most home laser
printers this translates into using less than 10 or 20 watts (see:
http://www.energystar.gov/index.cfm?c=printers.pr_crit_printers), and in many
cases machines significantly exceed the spec, e.g., drawing 1 watt or less
when powered off.

So... one pretty much has to look at the product's manual to determine just
how power hungry it is, and decide for themselves whether or not that amount
of power is "significant."

 

[Joel Kolstad]

John,

You make good points, but I think you're being a little bit too black and
white about this. There _are_ effective EMI/RFI filters out there, but I
agree with you that pretty much anything that doesn't have real test results
with numbers is probably entirely hit or miss as to whether or not it's going
to do a lick of good. Additionally, what many people don't realize is that
most appliances have plenty of EMI/RFI filtering built-in, since it was needed
to pass CE or FCC certifications, so any provided in a power strip may be
redundant.

Meanwhile your logic is that if a fan in a printer or a car runs
after power off, then if fan does not run, damage will result.
Nonsense. Spin that only a politician could love. Does the laser
printer or car get hotter when powered off? Of course not. If a fan
does not spin, the laser printer and car still cool - just slower.

Although an unpowered device can't generate any new heat, what _can_ happen is
that the heat that's still present when the plug is pulled can distribute
itself differently than if the fan is allowed to run, and this can potentially
damage other components. An example would be something like a video
projector... with a fan going, the heat from the bulb is shunted away from any
run-of-the-mill components, but if the plug is pulled those components can end
up being exposed to temperatures well outside of their specified range.

Makes no difference whether power is removed by printer switch, power
strip, or wall switch.

As a practical matter for a single printer, I suspect you're correct, but I
also believe that statistically speaking you would end up with more product
failures using a wall or power strip switch. For big companies with hundreds
or thousands of printers floating around, this is significant.