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by Martin 095 on Fri Jul 07, 2017 12:21 pm
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Hi,

My old UPS died not too long ago, and I need a replacement.  When I bought this unit, I still had a small printer (Epson 2200 I think), so at the time I was only concerned about my Mac.  Now I want a new UPS that will be sufficient for my 2008 Mac Pro (2.8 GHz Quad-Core Intel Xeon, purchased new in May, 2008) and my Epson 4880 but I have a few questions that hopefully someone can answer for me:

1) I am not sure how to correctly determine how many VA or W I need – is there a calculation for this?
2) Is there a preferred maker?

My old unit was a Cyber Power 1500AVR – this worked well for my Mac but I presume I need a larger unit to support both the computer and printer.  TIA!
Best wishes,

Martin
"If there is a sin against life, it consists, perhaps not so much in despairing of life, as hoping for another life and eluding the implacable grandeur of this life." - Albert Camus
 

by Rhett on Fri Jul 07, 2017 2:43 pm
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Typically UPS systems have two banks of ports. One with a battery backup, and the other with just surge protection. You may be able to just connect your PC to the battery and use the surge on the printer. If that's the case, it sounds like you can get by with a 1500VA model. VA is apparent power. You have to use the efficiency rating to calculate the Wattage.
 

by Martin 095 on Sat Jul 08, 2017 8:09 am
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Thanks Rhett – perhaps I am being overly cautious, but sometimes in severe thunderstorms we lose power momentarily and I would like to ensure power to both my Mac and printer is not abruptly cut off (or at least have enough time to shut them down properly).  So I would like to have a battery backup for both, and preferably in one unit.
Best wishes,

Martin
"If there is a sin against life, it consists, perhaps not so much in despairing of life, as hoping for another life and eluding the implacable grandeur of this life." - Albert Camus
 

by jgunning on Sun Jul 09, 2017 8:54 pm
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Martin, living in Florida with our thunderstorms, I needed backup protection for my computer and Epson 4800. I have an APC XS 1000. It was a replacement for a slightly larger unit, It will operate my desktop, printer, router and cable modem, but there is a time limit on that. The real capacity question is how long will the battery be able to run what you have connected to it. In my case I think the total rating on my unit was about 650 watts at the maximum.
 

by Andrew_5488 on Mon Jul 10, 2017 1:02 pm
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Martin 095 wrote:
Hi,


1) I am not sure how to correctly determine how many VA or W I need – is there a calculation for this?
2) Is there a preferred maker?



If you go to APC site you'll find calculator or wizard there.
 

by signgrap on Mon Jul 10, 2017 2:13 pm
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I understand your desire to UPS your printer but if it were me I'd size the UPS for backing up my computer and modem only. If you calculate the cost of doing another print vs how much addition UPS you'd have to buy just to save the cost of a print - seems to me the cost of additional print is far less expensive. You never in the lifetime of the UPS be able to save enough money to justify the additional cost of a larger UPS.
Dick Ludwig
 

by ChrisRoss on Wed Jul 12, 2017 3:48 am
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It depends on what you want to do with the UPS, If you want it to finish the print for you then you potentially need a bigger one. To size the UPS do the following:

Look up from the specs the power draw for your equipment you want to protect and add them up. The power should be in Watts.

Power then equals volts x amps so this is why you see UPS spec-ed as xxxxVA, the VA stands fro Volts times amps. But you'll see that the 1500VA unit is specced at 875W or about 60% of V x I. So take you power draw divide by 0.6 to get VA, As the power comes from a 12V battery you can then divide the VA by 12 to get amps and then calculate amp-hours, which is the battery capacity.

The monitor will be straight forward, the computer will be rated at a high wattage but in practice does not draw this unless running flat out. The specs for the printer state that it draws 59W or less which is pretty low and 5W on standby so you could probably let it finish the print once the power is gone. Whether you can do this or not will depend on the A-hr capacity of the installed battery and how long it takes before the computer has spooled the job to the printer's RAM.

The Printer draws 59W (or less), the computer 275 W at idle and a monitor might draw 50W or so if it's an LED monitor. So you are looking at 385W which is 640 VA and the draw is 53 amps. Running for 5 minutes is 53 amps x 5/60 = 4.5 Amp hours

It looks like the APC 1500VA unit has 2x 9 A-hr battery so running that for 5 minutes would use 4.5 amp-hours which is 25% of rated capacity. Normally you should only draw a battery to 50% of rated capacity to avoid damaging it and losing capacity. So running your setup for 5 minutes should be OK. If the computer has spooled the job across to the printer you can shut it down straight away to extend the UPS life.

So the sequence would be confirm the computer has spooled the job to the printer, shut the computer and monitor down. Let the printer finish then power it down. I believe you can shut down once the job has dropped off the print queue and the printer will finish it off. But you would need to confirm that. You can check how long the job takes to drop off the queue anytime and the whether the job finishes off properly of not first time you use the UPS in anger.

Whether you let in finish or not will depend on how long you estimate it'll take to finish.
Chris Ross
Sydney
Australia
http://www.aus-natural.com   Instagram: @ausnaturalimages  Now offering Fine Art printing Services
 

by Martin 095 on Fri Jul 14, 2017 5:29 pm
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Thanks for all the help. I am not worried about the printer losing power while printing, but rather, each time power is abruptly cut to the unit, my LCD screen flashes a message saying the printer needs to be serviced by an authorized Epson technician (or something along those lines). I was (am) worried that abrupt loss of power can damage the print head. If I know I will be printing over some time, I tend to leave the printer on, because I have found (this is admittedly not a controlled experiment) I have fewer issues with clogged heads. The printer doesn't pull much power when idling anyway, (or even when it is being used).
Best wishes,

Martin
"If there is a sin against life, it consists, perhaps not so much in despairing of life, as hoping for another life and eluding the implacable grandeur of this life." - Albert Camus
 

by jgunning on Tue Jul 18, 2017 1:42 pm
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Martin, I have gotten that message a few times. I simply turned the printer off and after a few seconds back on again and the printer reset and the message went away. No harm done that I have been aware of.
 

by Martin 095 on Tue Jul 18, 2017 3:29 pm
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Thanks jgunning.  I have been able to get around the error message by the same method, just wasn't sure if I was damaging my print heads, which as I understand it, would be expensive to repair or replace.  An ounce (or a gram for our friends everywhere else) of prevention ...
Best wishes,

Martin
"If there is a sin against life, it consists, perhaps not so much in despairing of life, as hoping for another life and eluding the implacable grandeur of this life." - Albert Camus
 

by ronzie on Tue Jul 18, 2017 7:01 pm
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I found out quite some time ago that the "non-UPS" receptacles were included in the measured load on my 1500 VA APC standby supply. I had to start it up with the printer off. It has to do with surge power draw. With all I have added my inkjet Canon I leave off. On the battery protected receptacles I now have managed router/switch, DSL router/modem, monitor, PC (switched off on start), NAS, and a couple of minor items. When AC is lost, I get 45 minutes to save and shut down. My main all-in-one laser printer is not on the APC but the inkjet 5 head Canon PIXMA MG6320 is.

When I run the power-fail test cycle, sometimes it fails when coming back-up if all is turned on. My steady-state power draw is only 112 watts on the battery with the inkjet off.
 

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