Hello I'm an ICT (InfoComTech) US Peace Corps volunteer deep in Tanzania who has the task of managing and advising concerning our college's two SunFire Sun Ray Servers and Dell Proxy server (on 2 Tripplite 2000VA rackmount Server UPSs and behind 30A AVS). We have about 100 SunRay thin clients (unprotected) and 15 Windows desktops (mostly on high end desktop APC UPS), an unprotected projector, and three laptops (on voltage regulators). There are overworked nationals who also advise on the equipment but they don't have any more expertise on the power issue than I. Any solid, referenced advice offered might apply to thousands of computers in country.
The power quality here is fantastically bad. The dam which generates the power is at least 350mi away with likely only one path between it and us, much of it rather low capacity wiring. Power cuts at least once a week. We run a large generator once a week as well. Brownouts with only one phase active happen monthly (I don't pretend to understand "phases").
In the most general way possible I'd like to ask what is the difference between these various sorts of power protection I've identified since I've arrived in country. What is the efficacy of each and how might they be combined? What is the cost effectiveness for amount of computers covered. Which ones count as "filtered power"? When don't specific solutions apply? I'm sure I'll be advising on all possible permutations.
- Surge Protection (e.g. Power strips from APC)
- Seem simpler but I am worried they are simply dressed up fuses. I combine with voltage regulator at my house. Expensive as only good brands trusted are imported from America and marked up.
- Why are laptop versions so much more expensive? More goodness or greedy markup?
- Voltage Regulation which smooths voltage +-50V from in my case, 230V.
- Very cheap imports available. Some seem functional. Laptop hard drives anecdotally seem to fail less when one is used (this possible?). At least puts another layer between you and bad power but I have seen UPS behind them fry when big power spikes occur.
- Would these be unnecessary in case of SSD/flash-based netbooks since there is no motor? LCD monitors?
- I swear I've seen flywheel-esque versions of these in old labs: possible?
- Uninterruptable Power Supply (UPS) which helps computers to shut down properly, high end versions also seem to include voltage regulation. Expensive per computer.
- At a college with a set up similar to ours, one of the rackmount UPS with voltage regulation fried so this is presumably not sufficient for the main equipment.
- Automatic Voltage System (AVS, likely proprietary name) which is commonly used in country at all manners of establishments where high tech is used and advertises "multiprocessor" controlled voltage switch which purports to protects a lot of equipment (15A, 30A, and 100A models available) on a circuit from bad power by cutting immediately if it senses badness. Power is returned after a timer is satisfied. Cheap per computer once you get past 2 or 3 desktops.
- In my experience we've had 4 of these blow around our campus with nothing behind them dying--A win, despite dropping $90 on each!
- Transformer: We don't have one of our own and I wouldn't think of recommending one but I've heard that some outfits spend thousands of dollars on a dependable transformer for compounds. True?
Also how does the generator play into this? If our compound is switched onto the generator as the generator is turned on, might the bad power which flickers the lights damage something?