By Steve McEvoy, Technology Consultant
Is Your UPS Connected Right?
If you have a ‘Server’ in your Practice (a computer that holds all your precious data), it’s probably protected by a device called an Uninterruptable Power Supply (UPS). The UPS’s job is to keep the Server running for a short period of time in the event of a power failure. They are essentially a small battery pack. Servers shouldn’t just be switched off in a power failure else you run the risk of corrupting data that was in use at the time (like your Management software that runs your Practice). You could even corrupt the entire Server operating system leaving it unusable. A properly installed and configured UPS is your protection against this corruption. I say ‘properly installed and configured’ because in many offices this is not the case.
In Part 1 of this article we covered watching out for Surge Only ports and linking the UPS to the Server with its Communication Cable properly. Here are the final few issues that you should check on for your Practice.
You Get What You Pay For
A UPS is designed to generate AC power (Alternating Current – same as your building) when your power fails. They do this using batteries contained within the UPS. These batteries are like the battery in your car and they store DC (Direct Current) power. All UPS’s generate AC power from its DC reserves, and this is done with an AC/DC power convertor. The problem is not all power convertors are created equal, and lower quality units generate a ‘Stepped’ or modified sign wave rather than a pure sign wave that your Server prefers/needs. They do this because it’s cheaper to make. A simulated stepped sign wave can cause all sorts of odd problems for your Server. I’ve seen Servers that don’t power up every time or run at all when on UPS battery power, some that reboot randomly, and other power related issues. You may not even know you have this issue (yet – until the power goes out). All of these issues can result in corruption of your data. You should verify that your UPS is a true sign wave model by looking up the specifications online. If you need a new UPS verify this prior to purchasing.
Figure 2 – Depiction of a Stepped Sign Wave DC to AC power conversion vs. a true Sign Wave
Figure 3- Specifications of a UPS with a true Sign Wave output
Figure 4 – Specifications of a UPS with a Stepped Sign Wave. Note the listing of some Surge Only plugs
Batteries Wear Out
Just like your car battery, the batteries within a UPS have a limited lifespan. I expect them to last 3 to 5 years at the most. This means that they usually do not outlast the life of the Server. If your UPS is more than 3 years old it might not be providing the protection you think it is. In the worst cases, I’ve seen old batteries unable to keep the Server up for more than a handful of seconds, not enough time to allow an orderly shutdown. If this was the case, you could be risking data corruption. Many UPS’s have built in periodic self-tests to watch for this problem, and typically will turn on some form of LED saying ‘replace battery’ if it needs servicing. Personally I recommend that you undertake a ‘calibration’ of the UPS once every six months. A calibration will simulate a power failure and times how long the battery will last prior to depletion. Since it’s an actual test, you can trust the result. If the UPS has insufficient runtime when on battery it is time to do something about it. Most UPS’s have replaceable batteries, and I would say this is a good option to follow if your UPS is properly installed and configured already as noted above (why have to go through all that setup with a new UPS if you can just rejuvenate your old one). The battery won’t be cheap, but it will be less than the price of replacing the UPS. Installing it is usually a fairly simple process, but be sure you do it with the Server OFF and follow the manufacturer’s instructions. Be sure to recycle that old battery.
Figure 5 – Typical UPS Replacement Battery
Pull the Plug
Once you think you have all these issues in order, you might consider a real life test to be absolutely sure you have it all configured right. Pull the plug (the main power cord to the UPS) to make the power fail, and watch ALL the results until the Server has shut down properly. Plug the cord back in and see if it all starts back up. Make sure that everything that ‘should’ happen actually does. Do this when the Practice is closed and shutting down the Server won’t be a disruption. Not the most exciting way to spend 20-30 minutes of your life, but taking the time now to be sure the entire system is working right can give you some peace of mind.