Using a generator as a source of power for your computers isn't as straight forward as you might think. Having continuous power for computers and other office equipment may be a necessity if your business is to survive an extended power outage. But what does it really take to accomplish this?
With the dependence on technology today it is not only prudent but necessary to protect sensitive computers and electronic equipment from power related problems. At a minimum, all equipment should be protected from power surges. This low-cost protection prevents damage to equipment from lighting and other power surges. Although this will prevent damage to the hardware itself, it does nothing to prevent the data corruption that occurs when computers are shut down unexpectedly. The solution to this problem is the installation and use of a properly sized and configured UPS (Uninterruptable Power Supply). A UPS monitors the line power and when the power is not within normal parameters, the UPS switches to batteries until normal power is restored. If normal power is not restored within a reasonable amount of time, then the UPS signals the computers to shut down. This allows the computer systems to shut down cleanly before the UPS batteries are drained and can no longer provide sufficient power to keep things running.
As you can see, a UPS provides a valuable and necessary layer of protection. But a UPS isn't designed to keep things running for long periods of time. They only provide protection from sudden and unexpected shutdowns. For longer term protection many business owners are turning to portable generators as a backup source of power. This sounds simple enough; buy a generator, a few extension cords, a can of fuel and you're ready to go. Well not exactly, and this is where you can get in serious trouble.
If you think that a portable generator will provide clean and consistent power, think again. Although portable generators have become more reliable and very affordable, most don't provide clean power. The frequency and voltage may vary so much that certain electronic equipment may not function properly, if at all. Then there's the problem of shutting down unexpectedly or when the generator needs to be refueled. You may think the solution is to simply plug all your computers and electronics into a UPS, then plug the UPS into the generator. When the generator shuts down, the UPS takes over until the generator is started again. Again, this sounds great in theory.
If you connect your UPS directly to a generator you may be surprised to find that your UPS may not accept the power from the generator at all. Remember, a UPS monitors the input power's quality and if it's not within acceptable ranges, it switches to the UPS's batteries. You could find yourself checking cables and circuit breakers wondering why the UPS is not getting power from the generator. The reality is that the UPS is getting power from the generator but the UPS does not consider the power quality to be sufficient. So what do you do now? There is no single solution. Start by examining your entire configuration. First, the generator must be powerful enough to supply consistent power quality. This means that the generator should be able to provide the same quality of power as the the power demands change. You may find that the generator may need to be much larger than your actual power needs. One of the most common problems with generator output is the line frequency. Generator output frequency should be 60Hz. My experience has shown that many generators are off by a bit. Purchasing a line frequency meter is a good investment. They cost little and are well worth the money. Adjusting the governor on the generator is a simple matter. The frequency should be set to 60Hz. If the frequency varies significantly as the load on the generator changes, consider a larger generator.
Make sure that your UPS is generator compatible. You may check with the manufacturer or visit their web site for information on compatibility. If your UPS has a sensitivity setting, reduce the UPS sensitivity to power fluctuations. If your UPS switches between battery and line power constantly, or remains on battery power the power quality may be inadequate. Reducing the UPS sensitivity may resolve the issue.
It is worth noting that appliances, lighting, etc. are not as sensitive to power quality issues. It may be more cost effective to have a generator dedicated to computing and telephone equipment and another for lighting and appliances.