APC does not recommend to connect AV equipment to back -ups...read

sound like APC Back-UPS for computers is junk according to APC that is.

It sounds like bull-$hit to me...

The unit you are using, BE650R actually only outputs 390watts. You need a UPS that outputs 2 to 3 times the total wattage from your PJ.

The email you received from APC support sounds like CYA.

I had an APC RS1000 I was using for my PJ and it developed a bad cell. I chatted with APC and told them what was going on and how I was using the UPS. They told me it was a bad UPS and replaced it with an RS1200. I have not had any trouble from the new unit. They did not tell me not to use it on a video projector.

You definitely want to avoide any UPS that uses a standard square wave, but those that use a modified square wave also described as "stepped approximation to a sine wave" should be ok.

Modified square wave still provides a horrible amount of harmonic content to your equipment. Slightly different, but similar harmonic content.

Audiophiles and high-end audio equipment owners will benefit from true sinewave products. Here are some further notes on the subject:

In general, any device that senses either voltage peaks or zero crossings could have problems when running from MSW. Devices such as these should be run from TSW inverters. Ham radio and CB radio operators may notice RF noise from MSW inverters; in that case do not run the radio and the inverter at the same time. Electronics that modulate RF (radio frequency) signals on the AC line will not work and may be damaged. You may notice hum or buzz in the audio of TV’s, radios and satellite systems used with MSW inverters. Audiophiles or professionals using sophisticated audio, remote measurement, surveillance or telemetry equipment should use TSW.

Examples of problem devices are motor speed controllers employing triacs, and some small battery rechargers that do not incorporate a transformer between the utility power and the load. To help you visualize this, if there isn’t a ‘wall wart’ between the battery charger (or the battery in the device) and the AC plug, don’t use MSW.

Please note two other common problem loads, electric shavers and emergency flashlights. Both of these items have batteries in them but connect directly into the wall to charge, without an external transformer. Don’t use items like these with an MSW inverter. If you do use an MSW inverter with a transformer-less charger, your product will likely be damaged. Garage door openers, laser printers and large strobes used in photography have all been reported as trouble loads for MSW inverters; they either don’t work at all or stop working entirely, so don’t take a chance – use TSW.

As a general rule, products operating through an AC adapter will work fine from an MSW inverter. These include laptops and cell phone chargers, video games, camcorder and digital camera chargers. Televisions generally work well; some VCR’s with inexpensive power supplies run poorly.

The XS900 puts out 540 watts so if your PJ uses a total of 275 watts, you are just short of 2X PJ power consumption. You could try it just to see if the 650 was simply no longer able to keep up with your PJ.

That's good info... but.. what do you recommend then?

Here's a true sinewave ups from APC:

http://www.apcc.com/resource/include...ase_sku=S10BLK

This one is more reasonable on price but not as many watts either:

http://www.tripplite.com/products/pr...productID=3071

Edit: Upon further review, it appears to not be TSW. Explains the price break.

I run my HC1500 off a Tripp-lite Smart 1000LCD. It works fine for me.

Unless you have a large number of power outages... I would not use anything. Chances are, the UPS will never have to be used and all you are doing is replacing it every three to five years anyway.

There are plenty that will tell you do nothing but bad residential power has taught me to protect things in order to get more life from them. I think your current ups is probably just underpowered. Get one that is 2 to 3 times the watts, not volt-amps. You will be fine. Our power goes out 2 to 3 times a year, right in the middle of the evening typically because everyone is coming home and turning on all their power hungry devices and then a transformer blows somewhere.

When the power goes down you most likely will turn the pj off in less then 1 minute, and the fun that cools the bulb takes only what 20 watts?

Power-down is not the problem, power-up is. A PJ pulls more wattage starting up than when running or shutting down. Typically, you are supposed to use a UPS that equals twice the wattage you are averaging for the total of your equipment. If you put a UPS on your system that only equals the same wattage, you will most likely not only not get one minute of time to shutdown but the UPS will not even try to cutover but shutoff instead. I have enough wattage to keep watching even if the power stays off for awhile. My dvr is setup with another UPS that will run it for up to 2 hours if the power fails. I'm not going to miss something just because the power failed at the least opportune time.

This is a good discussion that pops up about every six months around here. Most often you end up with the "get a better unit that's not square wave" being the general consensus.

I do recall one time a poster including an email he received from Optoma Tech Support indicating that it didn't matter what type of UPS you used because it is basically a PC-type power supply in the projector that converts the power to DC for internal use...

Who knows what to believe?? Cheers!

All power supplies used in home A/V convert the power to DC for internal use so that's not the issue. The question is how the conversion is done and how immune from external purturbations the internal DC is. Optoma and others may use switching supplies which are more immune than traditional linear power supplies. The fact remains that there is no disadvantage to better sine-wave AC except the cost.

Had to look that one up.

Hmm.. 1200LCD $160 or APC for $800... easy choice.

Too bad BB only carries the 1000LCD at above list price.. bastages..be perfect for gift card usage. Dang it.

When the UPS is new, the battery cells are fresh and hold a complete charge. After use for awhile they don't hold as good a charge and therfore start to have performance limits. Another reason to get one that is 2 to 3 times the total watts of your PJ.

Have you tried the ES900 yet?