Buzzing from LCD TV when on battery from XS1500

[wagswvu_apc]

This was originally posted on APC forums on 12/19/2010

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Long story short, I just replaced a XS1300 with a XS1500 on my entertainment system. However, I just noticed that when the XS 1500 switches to battery it causes my Samsung LED 6000 series TV to start buzzing ( can be heard from the back), I never had this issue with my XS 1300 that was on their originally.. Is this a bad thing and should I be worried?

[BillP]

This reply was originally posted by Angela on APC forums on 12/20/2010

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can you provide the exact models of UPS that you had? was it BX1300LCD to BX1500G? usually buzzing means that the device does not like the step approximated sine wave being output by the UPS while is on battery. if you went from an older unit to the newer model that i just mentioned, these two devices are different hardware platforms so something may have changed.

let us know and we'll check to be sure. the BX1300LCD was a gray unit with red LCD and the newer unit is black with LCD with white letters/numbers.

[j0235_apc · Accepted solution]

This was originally posted on APC forums on 1/16/2011

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Your ups has a built in power inverter, which changes the battery voltage from D.C. to 120 Volts A.C.
The inverter is not pure sine wave, It is a modified sine wave, which is know as square sinewave.
It is normal to hear buzzing sounds in tvs, radios etc. even in a lamp...