Plugged in a portable heater to the APC 650 unit and it immediately emitted a loud continuous high pitched sound.

[tekwrite]

Will the APC unit be okay after I unplugged the heater?

[JonPro · Accepted solution]

Hi @tekwrite 

From the description that you have provided, the UPS has encountered an overload.  You may remove the load, and restart the UPS.  You can also do a full logic reset on the UPS, refer to the FAQ articles below for your perusal.

• How to Brain Dead a Back-UPS unit. (Full UPS Logic Reset) - FA158947 
• Why might the Overload LED be lit on my APC Back-UPS? - FA158830 
• Why are the Overload and On-Line LEDs flashing on my APC Back-UPS? - FA158840