How to size an UPS
Sizing a UPS - UPS means determining the power needed to protect the loads connected to it.
Calculate the power of your UPS by following this simple procedure:
- Make a list of all the equipment that needs protection, remembering to include monitors, terminals, external drives, etc. and any expansions you intend to carry out in the near future.
- Each device operates with its own voltage (normally 230 V) and amperage (A). Write down these two values usually indicated on the rating plate on the back of the appliance. The power value in Watt (W) is rarely indicated.
- Multiply the two values to obtain the required power in Volt-Ampere (VA).
- Add the VA (or W) related to each device to be protected.
- The resulting sum value corresponds to the apparent power in VA (or active power in W) of the UPS you need.
TYPICAL POWER ABSORBED BY A COMPUTER LOAD
- Network server without monitor - PC Tower = 300 - 400 Watts
- PC without monitor = 200 - 250 Watts
- PC with LCD monitor = 250 - 300 Watts
- Needle printer 80 columns = 60 - 80 Watts
- Needle printer 136 columns = 150 Watts
- Modem = 30 - 50 Watts
- Hub 8 ports = 20 - 50 Watts
- Hub 16 ports = 80 - 150 Watts
- Thermal paper fax = 50 - 100 Watts
- Plain paper fax = 100 - 500 Watts
- Scanner = 40 - 80 Watts
To ensure the safety and correct operation of the UPS, do not connect photocopiers, laser printers or any other type of inductive load.