Issue:
Customer's device is emitting a high pitch hum or buzz.
Product Line:
APC H Type Power Conditioner, Line-R Automatic Voltage Regulator
Environment:
N/A
Cause:
Uninterruptible Power Supplies, Power Conditioners and Voltage Regulators are all power conversion devices. These devics all utilize electrical components such as transformers, coils and inductors in the process of manipulating input power, to provide adequately filtered output power to the attached devices. These components all use electromagnetism while converting utility power from AC to DC or while boosting/trimming low/high utility voltage. The magnetic flux generated by these components may fluctuate magnetic fields rapidly, causing the component to physically vibrate. This high frequency vibration can often manifest itself to the user as a high pitch whine or buzzing, depending upon the frequency itself. These frequency are most often outside of a human's normal range of hearing and are therefore rarely observed.
Resolution:
Unfortunately, there is no method of reducing this noise in the device once in service.