Power Requirements for PCs

Add VA requirements for all components. To find VA(VOLT-AMPS), find the Voltage and Amperage requirements for each piece of equipment. These numbers should be on a sticker on the back or bottom of the equipment. Then multiply the numbers together:

VA = Volts x Amperes

If your components are measured in Watts, then multiply the number of Watts by 1.4:

VA = WATTS x 1.4

Add the VAs of each piece of equipment to find the Total VA. If you cannot determine the VA for your equipment. You may wish to oversize the UPS to take into consideration future expansion needs.

APC says that a 1000VA UPS will support a 100VA device for 2.25 hours.

Measured components (with Clamp Meter Amps RMS) Continuous power numbers are from the equipment sitting idle.

Computer : PentiumPro/200, 96MB, 4.3G HD

• Startup : 1.35A
• Continuous : .7A - .9A

Monitor: Viewsonic 15" color

• Startup : 1.0A
• Continuous : .9A - 1.0A

Monitor : Iiyama 17" color

• Startup : 3.5A
• Continuous : 1.5A

Workstation Volt/Amp Requirements (CPU + 17" monitor):

• Startup : 120V x (1.35 + 3.5)A = 582VA
• Continuous: 120V x (.9 + 1.5)A = 288VA

Server Volt/Amp Requirements (CPU + 15" monitor):

• Startup: 120V x (1.35 + 1.0)A = 282VA
• Continuous: 120V x (.9 + 1.0)A = 228VA
• Continuous CPU only: 120V x .9A = 108VA