Luminous Landscape Forum

Equipment & Techniques => Computers & Peripherals => Topic started by: Mark F on March 15, 2010, 06:43:30 pm

Title: Uninterruptible power supply
Post by: Mark F on March 15, 2010, 06:43:30 pm
The power went out this past weekend, right in the middle of printing....   Luckily I did not lose any data, although it took a long while for my Mac to fix itself (repair permissions helped). So its time for a UPS, but I recall reading somewhere that unless you get a giant unit my 4880 will suck so much power out of the battery that my Mac will not be protected.  Does anyone know if this is true? Also, how much capacity would you think I need to protect an iMac and 2 external hard drives?

Thanks.
Title: Uninterruptible power supply
Post by: martinreed22 on March 15, 2010, 07:05:14 pm
Quote from: Mark F
The power went out this past weekend, right in the middle of printing....   Luckily I did not lose any data, although it took a long while for my Mac to fix itself (repair permissions helped). So its time for a UPS, but I recall reading somewhere that unless you get a giant unit my 4880 will suck so much power out of the battery that my Mac will not be protected.  Does anyone know if this is true? Also, how much capacity would you think I need to protect an iMac and 2 external hard drives?

Thanks.
According to the 4880 User's Guide it consumes approx 55W. That is less than a typical LCD screen  

A 1200VA capacity UPS will probably do fine, should you 10 minutes at least for a Mac, screen and printer.

cheers, martin
Title: Uninterruptible power supply
Post by: PeterAit on March 16, 2010, 11:37:36 am
Quote from: martinreed22
According to the 4880 User's Guide it consumes approx 55W. That is less than a typical LCD screen  

A 1200VA capacity UPS will probably do fine, should you 10 minutes at least for a Mac, screen and printer.

cheers, martin

Are you sure than 55w is while printing? Even so, I would not worry about putting the printer on a UPS - the worst that can happen in a power outage is you lose a sheet of paper.
Title: Uninterruptible power supply
Post by: martinreed22 on March 16, 2010, 01:00:14 pm
Quote from: PeterAit
Are you sure than 55w is while printing? Even so, I would not worry about putting the printer on a UPS - the worst that can happen in a power outage is you lose a sheet of paper.
Hi Peter,

I don't have a 4880 to hand to measure, but several Epson and third party websites quote the same 55W for operating power. Considering what it is actually doing, this seems fair. Different story for a laser printer . As a point of comparison, a 3880 quotes 25W and a 7880 also quotes 55W.

Fair point about only losing a page, however the original poster seemed concerned about this.

regards, martin
Title: Uninterruptible power supply
Post by: mahleu on March 16, 2010, 01:25:23 pm
Quote from: PeterAit
Are you sure than 55w is while printing? Even so, I would not worry about putting the printer on a UPS - the worst that can happen in a power outage is you lose a sheet of paper.

If the outage is from a lightening strike it can be a lot more than a sheet of paper. The power often spikes when it's switched back on as well.
Title: Uninterruptible power supply
Post by: Farmer on March 16, 2010, 11:01:04 pm
Definitely a max of 55W (for the earlier model, the 4800, was 59W), during low power it's less than 5W (ie idle).
Title: Uninterruptible power supply
Post by: PeterAit on March 17, 2010, 05:07:35 pm
Quote from: mahleu
If the outage is from a lightening strike it can be a lot more than a sheet of paper. The power often spikes when it's switched back on as well.

For that you need a surge suppressor, not a UPS.
Title: Uninterruptible power supply
Post by: feppe on March 17, 2010, 05:09:17 pm
Quote from: PeterAit
For that you need a surge suppressor, not a UPS.

A proper UPS protects from power surges.

Many (most?) surge suppressors are snake oil and do nothing to protect your equipment from power surges - fuses are much more effective.
Title: Uninterruptible power supply
Post by: ericstaud on March 17, 2010, 11:52:47 pm
Quote from: Mark F
The power went out this past weekend, right in the middle of printing....   Luckily I did not lose any data, although it took a long while for my Mac to fix itself (repair permissions helped). So its time for a UPS, but I recall reading somewhere that unless you get a giant unit my 4880 will suck so much power out of the battery that my Mac will not be protected.  Does anyone know if this is true? Also, how much capacity would you think I need to protect an iMac and 2 external hard drives?

Thanks.

It's pretty easy to look up the tech specs of everything you want to plug into the UPS.  Buy one with 30-50% more capacity than that.  You should also consider your modem, cordless phone, usb hubs, etc.
Title: Uninterruptible power supply
Post by: Mark F on March 18, 2010, 06:25:28 pm
Thanks. This has been one heck of a week. I've been offline due to another disaster, but have posted that on another topic.
Title: Uninterruptible power supply
Post by: feppe on March 18, 2010, 06:45:19 pm
Quote from: ericstaud
It's pretty easy to look up the tech specs of everything you want to plug into the UPS.  Buy one with 30-50% more capacity than that.  You should also consider your modem, cordless phone, usb hubs, etc.

Here's (http://extreme.outervision.com/psucalculatorlite.jsp) a very nice PSU calculator which I used when I bought a new PSU a while back. It can be used for UPS calculation as well.