AVRs (by APC)

Old No Comments on AVRs (by APC) 21

AVR stands for Automatic Voltage Regulator. They are also known by the name ‘power conditioner’. They are responsible for protecting our electronic equipment, yet few people know anything about them.

AVRs have been around for a long time. In the more consumer-minded and small business market, APC is essentially the only company offering them. These devices are significantly different than UPSs (Uninterruptable Power Supplies). UPS devices simply provide power when there is a mainline electricity interruption, or as we know it, a power outage. It will depend on the model, but they are configured to switch on after they see a predetermined drop in supplied voltage. For the entry-level APC units, this threshold is ~30 volts. So if the regular voltage out of a power outlet is 120 volts, then the UPS will switch on when it detects less than 90 volts being supplied.

The problems I run into aren’t so much damage from loss of power, but rather damage from low level power, or brown-outs. If, say, there is a low level voltage situation where we lose 20 volts of power, it isn’t enough to switch on the UPSs.

Electricity is pretty simple. There are 3 measurements to worry about, volts, amps and watts. When talking about AC (Alternating Current) power, the formula is volts multiplied by amps equals watts (volts x amps = watts). Say the average server is pulling down 550 watts of power to run. At a normal 120 volts, that’s 4.5 amps. In a brown-out condition of 90 volts, in order to continue to provide that 550 watts of electricity, amps go up to 6.1.

Now, without getting into too much technicality and laws of physics, amps are basically the measure of electrical charge passing through an electrical circuit. If the voltage drops and the amps increase, then the amount of charge is increased. This is why brown-out situations are dangerous for electronic equipment, and why hardware can fail or get damaged during these occurrences.

Automatic Voltage Regulators help us alleviate this problem, by stepping up low voltage and handling the increased amps before passing along a “clean” electrical current to your electronic equipment. Unfortunately, in my area, we often have these low-voltage situations. I’ve personally never seen equipment fail or get damaged during a full-on power outage, but I have seen equipment fail during or shortly after a brown-out.

Remember, UPSs are not ‘protection’ devices, they simply provide battery backup power in case of mainline electricity failure. AVRs are the devices that help protect our equipment from ‘dirty power’.

More information can be found at:



Martin Lehner

Martin Lehner is an technology professional working for an IT services firm in Whitehorse, Yukon (Canada). He has been working in the technology field for over a decade. With a degree in Business Admin and numerous industry certifications, Martin leads a team of IT professionals that provide third party support for clients. Originally starting a company to offer web development services, Martin quickly realized that clients wanted the entire spectrum of technology services. When Martin is not at work (which is not often, since his company offers 24/7 support), he is busy at home spending time with his family.

Related Articles

Leave a comment

Back to Top