Originally Posted by myoda
I don't put a lot of faith in devices that claim to deliver "clean" power. One more thing to look for in a UPS is automatic voltage regulation. When I had my Mits DLP, it was connected to an inexpensive Cyberpower UPS with AVR. I still connect anything with a hard drive to this UPS. 1 DVR, 1 HTPC, and 2 Western Digital WDTV live hubs and my Sharp lc70le640u are all connected. The power in parts of SW Pa is notorious for occasional quick outages, the kind where your power goes off for a second then comes back on. That type of quick on/off cycle can kill a DLP based display because the fan does not have time to cool down the lamp properly during the shut down process - the UPS kept the power going to all the devices without a hitch.
I agree with this post. You don't need a Pure Sine wave UPS, but Cyberpower makes Pure Sinewave if it makes you feel better for well under $150 for 600+ watts. I haven't changed my battery in 3 years on my CyberPower, and the battery is still fine. The key is to buy far more wattage than you actually need, as the bigger batteries will last longer on a scale basis of how much they can still output later on.
First off, killing the power to a projector is never a good thing. There are moving parts inside the projector that can get stuck (sure it's not super likely, but it definitely can happen), as I've seen it happen (color wheels, IRIS's, and other mechanical mechanisms in the LENS itself). Color wheel motors are based from hard drive motors (they are the same), so is it good to cut the power on your drives, exactly. There are more moving parts in projectors than there are in a computer.
The quick power power off/on's in a storm are what can really mess you up, the projector will not turn off instantly, it still holds a charge for a second. So those fluctuations during power on/offs are not good for it.
It is not just the lamp that is being protected when the fans are blowing as the projector shuts off, but the parts near the lamp (the lamp continues to emit heat) and in some cases if the parts have no fan near them, then the heat can "island" over a specific area and burn something up. I've seen lamps get so hot they melted the plastic around them and blackened the exit path. It just depends on how hot the projector and the room are when you shut it off, as well as the design of the specific projector you are doing it on. Some projectors are made to operate in higher internal temperatures than others. Some projectors just have heating design flaws. It's not like these engineers know everything about cooling, the fans are a precaution to ensure a potential increase in longevity. It is true that some projectors actually have an option in their menus to do INSTANT OFF functionality without fans going, but many of the larger home theater projectors are not made to do that. In general, there are more business projectors designed for that ability than HT projectors.
Regardless if a projector is designed for instant off or not, it's not that likely doing it a few times is going to hurt it, but it surely isn't going to help it. I personally would not do it, as it is just better not to. The only reason they add that functionality to some projectors is mainly for business meetings, to make it more convenient to shut off the projector instantly and people not sitting around waiting for the fan to stop so they don't have to talk above it, but running the FAN is the best bet. Not doing so isn't going to kill the life of most lamps (again depending on the individual projector and room temp), but it certainly is better to play it safe, and if the projector is running hot, there is a chance the fan can increase the longevity of the lamp (even just by protecting the housing itself). I've seen the wires melted on the housing before.Edited by coderguy - 6/24/12 at 3:47am