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Protection
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Protection
brought to you by PC Alamode Magazine | |
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Uninterruptible Power Supplies (UPS) were the subject of this column in September of 1996 and have been mentioned since then, from time to time, but always from the theoretical perspective. My wife, with a little guidance, gave me one for Christmas, so now there is some actual experience I can share with you.
How do you decide what size UPS you need?It needs to have enough plugs for all the equipment to be protected, including the telephone line for your modem. The plugs seem to come in pairs (two, four or six) and there need to be two RJ11/45 telephone jacks (from wall and to modem).But what if you want your computer to run unattended and to "gracefully" shutdown and startup when the length of a power outage exceeds the capability of your UPS? That capability requires a computer interface (serial ports), serial/RS-232 cable and software that will communicate between the computer and the UPS. Of course, this will work much better if your UPS is Plug and Play (PNP) capable. Since mine is manufactured by American Power Conversion (APC), that company will be used as an example. The only guide "before you buy" are charts on the box listing types of computer systems (Desktop PC, Desktop Multi-media System, Tower PC and High Performance Tower PC) against "Typical Battery Runtime In Minutes. The various UPS models are listed at the intersections.
I consider my computer [Pentium 133 MHz, 512 KB Cache, 2 MB VRAM, 48 MB EDO RAM, 2.4 GB Hard Drive, 8X CD-ROM, 3.5" and 5.25" HD Floppy Diskette Drives and a Tape Backup ] to fall in the Tower PC category. This gave me a choice of four UPSs, two in the 6-10 minute range and two in the 10-20 minute range. Since I wanted the automatic application and operating shutdown capability, that reduced my choices to two, one in each of the time ranges. Now the difference was down to price and the difference was approximately $100.00 between them. Cost was the deciding factor in purchasing the APC Back-UPS Pro 420 PNP The APC UPS Model Numbers (200, 280, 400, 420, 600, 650, 1000 and 1400) indicate the Volt-Amperes (VA) available. The two largest were not available in stock, but I am sure they could be ordered. In my September 1996 column, I converted the Amps properly (*120), but understated the Watts by .4 (*1.4) or 22.4 VA. My current system requirements are:
A problem is the VA conversion factors are in the User's Manual, not on the outside of the box. So, in getting the APC Back-UPS Pro 420 PNP, am I under protected? You would think so, even if you just considered the computer and the modem, which are the two items I plan to keep operating at all times, while the monitor, printer, speakers and woofer will be turned off. However, an Internet trip to http://www.apcc.com provides another evaluation. The Size-UPS for PC/Workstations WebPage has three areas that help you better define your requirements:
The result was Model # (BP420PNP), Receptacles (4), Run time at 150 Watts (10 minutes), % of Max Capacity Used (58 %), Product Line Information (Back-UPS Pro) and Voltage Out (120). I do not know how they came up with the 150 Watts (210 Volt Amperes) other than that working out to 50% of the rated value of one of their systems. Since my computer is open for other purposes, I looked at the power supply, floppy and hard drives, CD-ROM and tape backup, but could not find any ampere or wattage information. Therefore, I could not figure out what my actual configuration's electrical load was. It sure would be nice if there was some way this information could be easily computed. If I had just used the chart on the box, I would have never known if my protection was adequate. If I had only used the User's Manual section 13. (How to Determine On-battery Run Time), I would have had to return my Christmas gift and order a much larger model. Would have another brand like Best, TrippLite or UPSonic have provided any better information? No, the outside of the box is to sell product and the user manuals seem to work at having you purchase more protection than you might need. Thank goodness for the Internet. So after you figure out how much of an UPS you need, how do you select one. It is best to go to a store that has a choice of brands (you might have to go to several stores.) But, just how do you make your selection? If you are not familiar with any of the brands, look for the Underwriters Laboratory seal of approval on the box and other national and international certifications. Also, do they offer any insurance? Most of the middle and top of the line models carry a lifetime policy for $25,000.00. Of course, you have to install everything properly, have a grounded electrical system and make sure you have followed all their other requirements, but that is the way two-way streets are. If you are still having problems making a choice, check the consumer product guides and ask others, who have an UPS, why they bought the brand they have and how satisfied they have been with it. Like anything worthwhile, it is going to take a good amount of research and effort on your part to make a good purchase decision. How does my APC Back-UPS Pro 420 PNP meet my requirements?It has four electrical plugs, two RJ11/45 plugs, a serial computer interface, serial cable and their PowerChute Pro software. It was nice not to buy anything extra. The 18 page User's Manual is clearly organized and easy to understand. It is important to read it so you will know what all the panel (front and rear) indicators and switches mean and do. An unexpected benefit is a rear panel light indicating whether your electrical plugs are properly configured (polarity and grounding).Now to the software that controls shutting down applications and the operating system in case a power outage exceeds the time the UPS will continue to run your computer system. The model I bought was PNP and after I connected it and turned it on, my computer system recognized it and asked for the PowerChute Pro software to load. Once this TSR is loaded, a battery appears in the System Tray and if things are not correct, you get a message stating so, such as no communication with the UPS. This problem is well covered in the User's Guide (software documentation.) If everything is all right, the "+" and "-" in the System Tray icon will have a green background. The only two things you have to set in the PowerChute Pro software are the Shutdown Parameters on the Configuration Menu. There is one for Application and another for the UPS. Set the Application(s) to shutdown before the UPS and the UPS to shutdown before estimated Run time at 150 Watts. All this information it should make choosing an UPS much easier. One final thing; this purchase was made at CompUSA and I saved 31.8% over the listed and 34.0% from their normal price. Basically, it refunded me my past three years ALamo PC dues. Randy Waters is a computer programmer/analyst for your federal government, specializing in information protection (p.k.a. computer security), business recovery planning and operation system and application software training. The Microsoft Office Standard 97 SIG and the Help Committee in addition to this column are his contribution to APCO. S.A.I.L.S. and the First Presbyterian Church round out his community involvement activities.
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