[ale] OT need 600-1000W power protection for 3 minutes - cheap

Ron Frazier (ALE) atllinuxenthinfo at techstarship.com
Tue Jul 9 15:46:47 EDT 2013


Hi Alex,

Thanks for the BR/BX explanation link.  It looks like the BR series are 
better units.

Would you like to acquire another Smart UPS?  Mine is an SMT-750 (750 VA 
/ 500 W) less than 1 year old.  It works great and, as far as I know, 
the batteries are in good shape.  However, the more advanced features 
are beyond my needs and I do need the additional capacity of a BR1500G.  
The current amazon price is $ 272 for this unit.  I'll let mine go for $ 
200, which is a 25% discount.  I'll even deliver it within 30 miles of 
my house (from Cumming, GA, exit 16 on GA 400).

I probably shouldn't tell you this since I just asked you to buy this 
unit.  But, according to http://www.apcupsd.com/ , this unit will only 
communicate basic data to apcupsd, and will not communicate voltage, 
frequency, etc.

I was under the impression that computer power supplies were essentially 
(or appear to be) resistive loads.  As an example, my pc is currently 
running at a .98 power factor, almost as many watts as VA.  In any case, 
it psychologically bothers me to have to look at a box for an SMT-750, 
for example, and mentally convert and think, no, that won't power my 
530W load.  Oh well.

By the way, for those of you who would like to track the storms in the 
area in case you're worried about power glitches too, I've found a 
couple of good ways to do that.  I'm sure there are others.

Go here and get the Reload Every Firefox plugin and install it (if you 
use Firefox): http://reloadevery.mozdev.org/  Or, you can use the addons 
menu in Firefox.  There are many plugins with similar names though.

This will allow you to automatically refresh a web page on a schedule.

Now, go here to the AccuWeather radar page: 
http://www.accuweather.com/en/us/georgia/weather-radar

If you wish, you may use this page as is.  However, I find it convenient 
to search on my city.  This puts an image of a thumb tack at my 
location.  If you want to do that, first type your city, state into the 
search box and hit enter.  Ex: Cumming, GA.  Click the radar tab on the 
right.  This goes to an animated page, which is not what I want for my 
purposes.  Scroll down and click Classic Radar on the left bottom.

You should now have a static image of the south east radar with a thumb 
tack at your location.

Now, right click the tab you're viewing this in, select the reload every 
menu, and select an update interval of say 5 min.  The page will then 
refresh every 5 minutes.  You can confirm that the reload every is 
active by going back into the menu.  You should find 5 min selected and 
the "enable" box selected.  I don't think that it updates when the 
screen saver is on, so the first time you come back after a while, you 
may have to refresh the page manually.

The problem with this page is that it shows 6 states at once and our 
area is tiny.  So, as a final step, hit the ctrl + (control and the plus 
key) sequence 8 times to zoom the page in.  You could also use the mouse 
to go to the view menu, zoom, zoom in.  Now, visually adjust the borders 
of the Firefox window to about 4" x 3" in size (or whatever you want).  
Adjust the scroll bars to show the area of the state that you want.

This is harder to type than to do.  Ta-Da, you now have an auto updating 
customized radar picture for your area.  There may be other radar sites 
where this works better, but this works for me.  If you know of others, 
please share.  One problem is that some sites will lose the scaling and 
position when the page is refreshed.  Other web pages may show the roads 
and cities, etc.

For Android, I highly recommend Storm Eye: 
https://play.google.com/store/apps/details?id=com.cds.stormeye&hl=en

It overlays the weather radar on a google map with cities and roads.  It 
shows the track of the storms and eta to your designated location.  And, 
it auto updates.

Hope this is helpful.

Sincerely,

Ron


On 7/9/2013 12:45 PM, Alex Carver wrote:
> I have three APC SmartUPS and have no problem whatsoever with apcupsd 
> finding them.  I get emails when the system goes on battery and the 
> auto shutdown works fine across multiple machines with apcupsd sending 
> data to other machines hanging off the same UPS running apcupsd in 
> ethernet mode (no direct data connection to the UPS.)
>
> Here's your BR/BX explanation:  http://forums.apc.com/message/23515
> The difference between the SMT and the BR/BX is the Smart Slot where 
> you can add Smart Slot accessories like various management cards 
> (ethernet) with temperature sensors, etc.  Both the SMT and BR/BX have 
> the normal USB/serial data port for connecting to a single computer.  
> The Smart Slot just allows for direct ethernet connection and 
> management by SNMP and APC's PowerChute software.
>
> Measuring in VA instead of W isn't marketing rubbish (entirely), it's 
> proper engineering specification for AC circuits.  Unless your voltage 
> and current are exactly in phase at all times with no distortions at 
> all, Watts are meaningless unless you also specify VAr or the power 
> factor.  Volt-Amps eliminates the need for the power factor because it 
> represents the scalar length of the power phasor (vector) regardless 
> of where it's pointing in W/VAr space (the 2pi radian range of phase 
> angle.)
>
> Using volt-amps for the specification means that a power supply (the 
> UPS in this case) can supply varying types of loads with different 
> power factors and the total available apparent power (real and 
> reactive/imaginary) is constant.  A 100 VA motor and a 100 VA light 
> bulb require the same amount of apparent power.  The light bulb needs 
> mostly real power and the motor needs mostly reactive power.
>
> Where the marketing comes in is the fact that the engineers are forced 
> (by marketing drones) to pick an average power factor so they can 
> label the object.  Typical switching supplies (prior to a concerted 
> push against manufacturers by power companies to make them 
> electrically cleaner) have a power factor of 0.6-0.8 and some really 
> crappy Chinese knock-offs have power factors down near 0.4 with 
> hideous harmonics.  APC assumes a power factor of somewhere around 
> 0.65 for connected devices which is why your Watt rating is lower 
> because some of the available VA must be used for the VAr portion of 
> the load demand.
>
> On 7/9/2013 08:45, Ron Frazier (ALE) wrote:
>
>
>> Hi all,
>>
>> To be honest, I need to save some money for this project, since, when
>> spending $ 200 at a time, and multiple times, it adds up.  But, I hope
>> to implement it soon.  I might be able to buy one new unit, and reduce
>> the load on one pc to use my old ups with that.  Not sure yet.
>>
>> The more I think about my loads, the more I think I need a 1500 VA / ~
>> 900W unit.  A 1200VA/~700W unit might do it, but most product lines seem
>> to jump to 1500 VA after 1000 VA.
>>
>> The last time I bought a UPS, it was from Frys.  I have no complaints,
>> but you do pay sales tax and probably an intrinsically higher price. The
>> advantage is easier returns if needed.  I can't believe it, but I am
>> actually considering mail ordering a UPS.  I understand from Amazon
>> reviews on some, that you have to pay to ship it back to the factory if
>> there is a problem, which can be expensive.
>>
>> Based on prior discussions and my experience, I know APC is a good
>> brand.  I also understand that, for the "smart" units, it can be hard to
>> get linux to talk to it, if you want to use the auto shutdown software
>> like apcupsd.  I think you guys told me before that Tripplite is good,
>> so I may look at those.  Based on some amazon reviews and prior comments
>> here, it sounds like I should stay away from Cyberpower.
>>
>> I think it's total marketing rubbish that they rate these things by VA
>> primarily.  My computer is currently pulling 539 VA and 532 W, according
>> to the Kill-A-Watt EZ, with a power factor of .98.  The UPS I have is an
>> SMT-750 so you would think it could handle the load.  But NO, that's 750
>> VA.  The watts are limited to 500, so the thing yells like crazy if I
>> run this load on it.  (So I don't.)  So, it should be labeled SMT-500!
>> That unit was capable of handling the load before I upped the load. Yes,
>> I do know what VA means.  It's just difficult to remember to cut
>> whatever number I see on the box almost in half to get a realistic load.
>>
>> Charles, thanks for the links.  I'll keep the buy batteries local idea
>> in mind.  Might not be necessary with Amazon's free shipping.
>>
>> It's nice to see that the major makers are starting to come out with
>> some bigger units, with some smarts, with more reasonable price tags.
>>
>> That Fry's link you posted is actually quite interesting.  I found it's
>> bigger brother on Amazon.
>>
>> http://www.amazon.com/APC-BR1500G-BACK-UPS-10-Outlet-1500VA/dp/B003Y24DEU/ref=sr_1_1?s=electronics&ie=UTF8&qid=1373381258&sr=1-1&keywords=br1500g 
>>
>>
>>
>> APC's different model numbers are confusing.  For example, I don't know
>> the difference between a BR and a BX unit.
>>
>> This unit is a 1500 VA / 865 W unit, with lcd (or led or something)
>> status display, and AVR (automatic voltage regulation [very cool]); for
>> $ 179 with free shipping and no sales tax.  This unit has a BR part 
>> number.
>>
>> This is at a price point / capacity point that's really starting to get
>> my attention.
>>
>> Here's a similar unit at Frys.
>>
>> http://www.frys.com/product/5955004?site=sr:SEARCH:MAIN_RSLT_PG
>>
>> It has a BX part number.  Go figure.  The capacity is the same, but it's
>> $ 210, or $ 225 after sales tax.
>>
>> In any case, much better than the $ 500 Frys wants for the SMT-1500. So,
>> I guess the big question is, what do I give up by going with the BR/BG
>> 1500 and saving $ 300 versus the SMT-1500?  I'll have to do some
>> research on that.
>>
>> Alex, good point about the cooling.  If I'm using a stock battery and a
>> name brand, it will probably be ok.  If I'm using a non standard
>> battery, that may be something I have to look at.
>>
>
>
>
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-- 

(PS - If you email me and don't get a quick response, you might want to
call on the phone.  I get about 300 emails per day from alternate energy
mailing lists and such.  I don't always see new email messages very quickly.)

Ron Frazier
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linuxdude AT techstarship.com
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