An uninterrupted power supply (UPS) is used to provide backup power for a certain amount of time to your devices. It is a battery-operated device that is plugged into the mains (power at the wall) and converts the power from AC to DC and then back to AC and provides backup power for your critical loads.
UPS can vary in size from a small system at your desk to keep your computer up and running all the way to a large system to maintain a process at a plant.
A UPS provides a critical role in allowing you to save your important information or data on your computers or servers all the way up to allow you to keep a process up and running so that you don’t lose your product.
UPS can help a user ride through a brownout, also known as voltage sag. It could happen when you lose partial power or lose a leg of a 3-phase system. It is not like a total blackout when you lose power to the whole facility.
UPS batteries will last for a certain amount of time. It depends on what type of batteries you have inside the system. They can be sealed lead acid or lithium ION batteries. Also, it can depend on how much load and capacity you have on your UPS. A lightly loaded UPS can last for hours, whereas a fully loaded UPS will probably only last for minutes. On some UPS you can add external batteries to achieve longer run time. Adding more batteries to a system will not allow you to increase the capacity of the unit or the amount of load it can support. It will allow you to increase the run time.
Its good practice to size your ups and determine your loads and verify the power draw on each device. You will be able to size the UPS according to this and then determine how much Capacity or extra batteries you will need to get the runtime you need.
You should avoid putting high inrush devices like motors or laser printers on your UPS. They will quickly drain your UPS or cause it to go into an overload fault.
Most UPS will have surge protection outlets as well as surge + battery backup outlets.
UPS and Generators can be used in tandem. With a Generator and UPS system, you can achieve almost limitless runtime with the UPS providing the runtime while the generator gets up and running.
Online vs Offline UPS – Offline UPS is a type of UPS that will take the mains voltage and pass it thru to the loads connected. An Online or Double Conversion UPS always has the inverter and converter online. It takes the mains voltage and converts it to DC and trickle charge the batteries. It will then take the DC and invert it back to AC to provide a pure sine wave output.
Not all batteries need to be maintained. Some of the smaller units you will only need to replace the batteries. On some larger system will need to be maintained with fluid levels and trickle charging, as well as maintaining a certain temperature.
A Maintenance bypass allows the user to take the UPS offline if they need to do work on the UPS or replace it without having to unplug or unwire the loads.
UPS can play a big role in Automation projects as well to ensure that the PLC will stay up and running or that the IPC can gracefully shut down so you don’t lose any of your data or recipes.