Waveform of a UPS

Status
Not open for further replies.

mgookin

Senior Member
Location
Fort Myers, FL
Occupation
Retired inspector, plans examiner & building official
Just curious whether anyone on here has ever hooked up an oscilloscope to a UPS (120V) like you'd have at your PC. Since there are so many on the market I'll go find one online and be right back.....

... ok let's say it's something like this: http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=BR1500G&total_watts=200

When I look at the overview of their product lines I don't get any hits on a search for "sine" other than business.

If everything is normal, does the output produce a true sine wave?
And if it goes into emergency mode, does that produce a true sine wave as well?

Reason I ask is we are setting up some testing with very expensive equipment that will run for long periods and don't want to risk losing all that work or damaging equipment if these things are just going to invert dc power at 60Hz. We are in the Everglades so it's inevitable that we are going to lose power during the testing.

Is there a particular type, style or brand we should be looking at?

Thanks in advance.
 
Is there a particular type, style or brand we should be looking at?

Yep, I've 'scoped UPSs, also did a study of smaller units (<2kva) a while ago using a Fluke 41.

Generally, the cheaper the UPS, the worse the output waveform when on battery. Both the BackUps and BUPro are a stepped-squarewave on battery while the SmartUps is a reasonably well-shaped clean sine. Actual load will shift that, of course. At this point, I tend to prefer Leibert/Emerson over APC, the old GXT series was great (haven't tried a GXT3 yet).
 
Status
Not open for further replies.
Top