Print 🖨 PDF 📄 eBook 📱

Last week we had several power drops and sags during a rain storm. My Cycler had been set up and rebooted because of the storms. I had to go through the entire setup again with no assurances that another storm wasn’t in the making which would have invoked the same scenario again. This is not unique to me. On several forums, people have reported either weak power grids that often sag/drop, or storm-related droppage.

There is a simple solution to this problem which I have instituted – that of employing an uninterruptible power supply., or UPS as they are most often referred to. What a UPS is, is a battery-powered circuit (called an inverter) that changes battery voltage (DC) to 115VAC or common US household line voltage. Now we have to ascertain what brand to purchase, and what size for our Cycler application.

I know from my background in electrical engineering that APC (American Power Conversion) is the go-to company for UPSs so I started there. What size/power level UPS to purchase was my next concern. I wanted the UPS to be able to cover two situations – 1. Rather short power sags or drops typical during storms, and 2. Give me enough time if needed to bring up our standby generator in case of catastrophic power failure.

  1. First. The Cycler manual states the Cycler draws 480 watts max. This probably takes place as it is warming up the main tray solution bag and should drop to a lower steady state as the terminal temperature in the bag is reached. A rule of thumb in engineering is to double the requirements for a safety edge, so I specified the UPS at a minimum of 480 x 2 = 960 Watts.
  2. The second requirement is that the UPS be able to run the Cycler long enough for me (or my caregiver wife) to start up our standby power generator system. I figured half an hour should be plenty as the standby generator is always ready to go.

APC sells a model XM1500M UPS that is 900 watts which is close enough to what I specified. It has close to the times two wattage and will run the Cycler load for close to half an hour. That is the model I purchased from Amazon ($189.95 + tax) and is now hooked up to my Cycler to prevent power outages. See picture below. FYI, it switches to UPS in 8-10 msec when power drops – that’s 8-10 thousandths of a second.

Coming up I intend to spec out a poor man’s generator system to support running a Cycler in case of prolonged power outages.