Possible Bizarre APC Back-UPS Pro 650 Behavior

[chelovek_apc]

This was originally posted on APC forums on 7/11/2009

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Do I have a problem with my Pro 650?

Connected to the pro battery backup side are my PC, a flat screen monitor, cable modem, router, etc; connected to the filter side are my Lexmark Optra R+ laser printer.

This configuration, unperturbed, but for a UPS battery replacement 2 years ago, has been working for a long time, the UPS "clicking" when the printer switches on or draws power, such as during a printer thermal head heat cycle.

Suddenly, yesterday, after having had the PC on for several hours, I switched the printer on, and my PC shut down instantly. Problem repeatable, but not every time. Disconnected the printer data line, no change. Moved the printer off the ups to another socket on the same AC outlet, no change. Swapped the printer for an identical printer. No change. Switched on printer, booted PC, worked for a few minutes, then bam, the PC shut down hard.

Can some filter electronics have failed in the Pro 650 that allows surges, say when the thermal mechanism of the printer switches on, back upline into the UPS side and thus into the PC, which then senses the surge and shuts down?

By swapping printers, I believe I have eliminated the printer as a potential problem source. I can't think how the PC could be at fault - i.e., a partial power supply failure introducing extreme surge sensitivity. That leaves the UPS, but the failure mode of having the printer not connected to the UPS but both merely connected to the same AC wall socket, has me stumped.

Help!

[Techie_apc]

This was originally posted on APC forums on 7/12/2009

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Gary,

I suspect that the UPS transfers to battery mode whenever the printer in question starts/draws power. I think that the UPS is not able to provide power on battery mode. Connect a non critical equipment to the UPS battery backup outlet and stimulate a power failure by unplugging the UPS from the wall, and check if it powers the equipment on battery mode. If it does not support on battery mode, you may need to replace the battery. However, please verify the front lights indication before replacing the battery. The UPS performs a self test to check the battery integrity at start up and every 14 days automatically. What lights are on the front of the UPS after you switch on the UPS?

[BillP]

This reply was originally posted by Jonathan on APC forums on 7/12/2009

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One thing that comes to my mind when you mentioned about having a laser printer in your configuration is that due to the age of your UPS some mechanism of the unit might be failing. Whenever you start up your UPS or it heats up the thermal mechanism it draws a lot of current to do it and it is what do we call as inrush current. Certain UPS is sized incorrectly can go on an Overload condition which would then turn off the outlets on the UPS.

Listed below are some knowledge base articles that might help you learn more about Back-UPS.
- [Recommendations for protecting a laser printer|http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=23&p_created=1000309963&p_s...]
- [Equipment connected to a Back-UPS product turns off unexpectedly and/or reboots.|http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=20&p_created=1000309963&p_s...]

[chelovek_apc]

This was originally posted on APC forums on 7/13/2009

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Thank you for the suggestions. As I was reading your response, the two weeks must have ticked over, because the "bad battery" symbol began to audibly alarm and the X symbol indicator lght on the UPS came on. I would never have dreamed that the self-test interval was two weeks - two days max seems much more prudent.

As this would have been the second replacement battery, I plan to junk the UPS and buy a new one.

Thanis, again, for your ideas & recommendations.

Gary

[Techie_apc · Accepted solution]

This was originally posted on APC forums on 7/13/2009

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Gary,

You may also trade in your old unit to a new unit. Click on the below link to know more information about trade UPS program.
http://nam-en.apc.com/cgi-bin/nam_en.cfg/php/enduser/std_adp.php?p_faqid=298

Thanks!