Your Inline UPS corrects the power issues we discussed earlier and it also provides time for the system operator to save and close studies that may be in progress. This additional time will help prevent the corruption of patient data and the possible loss of access to your patient archive. These are high level functions not protected by the internal UPS.
Choosing a UPS.
You will need to know how much power your system requires. This will be specified in VA or wattage, both are numbers representing the output ratings of the UPS. A good rule of thumb for selecting a UPS is 80% of the UPS capacity. This will allow for loss due to conversion and allow for start-up current, unfortunately nothing is free.
“The VA rating is the apparent power, while the Watt rating is the real power (or true power). The difference between these two numbers is the reactive power. Reactive power arises due to the effects of capacitance and inductance of components in the load to be powered by the AC circuit. In a purely resistive load the apparent power is equal to the true power and the amount of VA’s and Watts used would be equivalent. However, in more complex loads, such as computers the apparent power used (VA’s) will be larger than the true power used (watts). The ratio of this difference is called the power factor.” Wikipedia
Be sure to ask what input power will be required. Your system may be happy with a 15amp outlet but the UPS may need a 20amp supply. That additional 20% capacity may push you input current up to the next breaker size.
What about maintenance?
Most UPS units require little maintenance. They should be clean and free from debris. This type of UPS is heavy and tends to disappear under a table or in a corner. They must have adequate airflow.
These units usually have resident self-testing which will warn the operators if there are circuit faults, internal failures and battery issues. Their batteries are typically sealed gel cells and are functional for 5 or more years. They should be replaced and disposed of in accordance with manufacturers’ recommendations, local and federal laws.