Sep 1, 2010, 10:50 PM
Post #4 of 5
In addition to battery back-up, good quality UPS's also provide prtection from voltage spikes, voltage surges, and consistently high voltage. The voltage protection functions can often be as or more important than the battery back-up features.
All 6 different models and brands of UPS's that cost less than $100 USD (including 2 Koblenz models) that I have tested have not provided the protection needed by some electronics. i.e. APC's small units that cost about the same as battery replacement costs ($40 USD) do not protect against slow power surges, nor do they protect your electronics from consistently high voltage, as often happens in Mexico.** I had an older robust HP laserjet printer ($600 USD model) fried when connected to a cheap APC UPS. APC fought over the problem for 2 months, including requiring that I ship the UPS back to them & they threatened that I would have to also ship the printer to them, but finally they agreed that their cheaper units do not protect against consistently high voltage. After months of technical discussions, they finally sent a check for the entire amount claimed for our damaged electronic equipment.
Specifically: One "110V" leg of our "220V" CFE service often spirals up to 133VAC to 138VAC, staying there for hours & days during low power usage in our neighborhood, which ultimately cooked some of our electronics. While the new APC cheaper digital units did not protect our electronics, our two old-school induction coil technology APC units ($120 new & $180 new with batteries that cost $40 USD - $60 USD) consistently regulate the high voltage down to safe levels (keeping voltages under 125VAC)
**Mexico's official policy is to provide AC power at voltages between 114VAC to 140VAC, which means that some of our appliances, printers, and electronics that work fine in the USA and Canada will instead need good protection and constant downward voltage regulation that is only offered by more expensive and older UPS's.
Office Depot had carried some better quality (a.k.a. more expensive = more than $100 USD) UPS's in the past. Unfortunately, it may take a good volt meter (DMM) to actually determine if your UPS is doing the job: i.e. check your line voltage and see if it exceeds 126VAC. If your line voltage on either leg of your 110V/120V power is higher than 126VAC, then check the output voltage of your UPS. A good UPS will regulate the voltage back down under 127V, while the newer & cheaper UPS's will not.
We've had great experiences with the following brands of more expensive UPSs and voltage regulators over the past 4 decades: Sola, Tripp / TrippLite, & APC. Also, if you have an old constant voltage transformer kicking around, they work great to to protect electronics & computer equipment from dirty power and high voltage (i.e. the transformer used by TV techs to float - isolate from ground - the TV while they are working on it.)
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(This post was edited by YucaLandia on Sep 1, 2010, 10:52 PM)