Which UPSes have AVR and adjustable sensitivity

Anonymous user · ‎2021-06-29

Which UPSes have the Automatic Voltage Regulator(AVR)?

Which UPSes allow you to adjust the sensitivity?

Will either of these features eliminate or reduce frequent UPS "clicks" due to voltage dips caused by a laser printer on the same circuit? (The laser printer is not connected to the UPS.)

BillP · ‎2021-06-29

Hi Jana.

I don't work for Schneider/APC and I can't tell you specifically tell you which families of UPS do or don't have either AVR or adjustable sensitivity but looking through their product line would help you determine that.

I can offer you my own personal experience with something similar to your situation. I have an SMX1500RM2U that I use to protect some electronics in my home theater system from power loss. The SMX1500RM2U that has both AVR and adjustable sensitivity. When I power on the home theater system the voltage on the one circuit sags enough to be detected by the SMX and causes it to attempt to regulate the voltage. There are no settings that I can make to the SMX that will prevent it from trying to adjust the voltage and making some sort of clicking noise. When I had the SMX set to maximum sensitivity, the unit would actually transfer to battery for a few seconds.

Although I haven't measured it with an oscilloscope, etc., the inrush current load on the the single 15amp circuit when the amplifiers are turned on causes the voltage to sag or distort the waveform beyond what the UPS can "ignore". I have been told that I need to install another circuit dedicated to powering the UPS-critical components if I want to eliminate the voltage sag.

A laser printer draws quite a bit of power when it's fuser starts to warm up and I am pretty sure this is what you are experiencing. How far the voltage drops in your specific case would determine whether or not you could desensitize a given UPS enough to ignore the sag.

See Answer In Context

BillP · ‎2021-06-29

Hi Jana.

I don't work for Schneider/APC and I can't tell you specifically tell you which families of UPS do or don't have either AVR or adjustable sensitivity but looking through their product line would help you determine that.

I can offer you my own personal experience with something similar to your situation. I have an SMX1500RM2U that I use to protect some electronics in my home theater system from power loss. The SMX1500RM2U that has both AVR and adjustable sensitivity. When I power on the home theater system the voltage on the one circuit sags enough to be detected by the SMX and causes it to attempt to regulate the voltage. There are no settings that I can make to the SMX that will prevent it from trying to adjust the voltage and making some sort of clicking noise. When I had the SMX set to maximum sensitivity, the unit would actually transfer to battery for a few seconds.

Although I haven't measured it with an oscilloscope, etc., the inrush current load on the the single 15amp circuit when the amplifiers are turned on causes the voltage to sag or distort the waveform beyond what the UPS can "ignore". I have been told that I need to install another circuit dedicated to powering the UPS-critical components if I want to eliminate the voltage sag.

A laser printer draws quite a bit of power when it's fuser starts to warm up and I am pretty sure this is what you are experiencing. How far the voltage drops in your specific case would determine whether or not you could desensitize a given UPS enough to ignore the sag.