Thread: How much powerful UPS and Battries Req. ?

Hello,
I do have setup of 10 PC's.
(all PC's have LCD screens, 18.5 inch wide.)
and 10 CPU's (P4 processor,945 motherboard.)
How much powerful UPS it will need and how many batteries I req., if I need 2 hours of backup ?
(10 LCD's + 10 CPU's)

previous thread ;
http://www.indiabroadband.net/buy-se...lculation.html (UPS capcity calculation.)

Switch on all your PCs/displays/modem etc
Check Electric meter reading. No of Units consumed.
say for 15 minutes one unit. 1 hour 4 Units. 4000Watts .

An UPS system capable of 4KVA ( with safety margin will . do )
Better to split the requirement to two UPS units.

More information
http://michaelbluejay.com/electricity/computers.html
microtek UPS

Feedback.

Step 1. Determine your computers power requirement.
This is usually dependent on the SMPS power consumption which comes around 150W for typical desktop
Your LCD monitor would appoximately need 40W.
Precise values can be determined from the equipment itself, usually written on its backside.
Consider, in your case 190W/PC
Since you have 10PC, total power requirement is 1900W.
Step 2 etermine backuptime, in your case, 2 hours.
Step 3 etermine Amp drawn from the battery.
Use the formula, Power (Watts)=Voltage (V) X Current (Amps)
Most batteries comes with 12V, or 24V. Consider 12V. (You may change this if you need to)
Your power requirement is 3400W.
So, Amps = 3400(Watt)/12(Volts) = 283 Amps.
This means you need a 12V battery rated at 283Amps to run 10PC's for 1 hour.
For 2 hours,. multiply the Amps X 2, 266Ah.
Step 4 :Once you arrive at the final Ah required, in your case, 266Ah, round off the figure to the standard battery values.
Check this with the battery vendors. (I think 300Ah)
Step 5 : Once battery size is determined, you can proceed selectiing the charger/UPS accordingly.

Hope you get an idea now.
You can also opt to have a 24V battey instead of a 12V.
This sizing mentioned above is the peak requirement. Take diversified load, and plan accordingly.
By the way, are you planning to open an internet cafe or what?

Cheers!

Originally Posted by nevinjohn

Your power requirement is 3400W.

Sorry for the mistake. The power requirement is 1900W.
So. Amps = 1900/12 = 158 Amps.

The battery requirement for 1 hour is 158Ah. Round it off to 160Ah, rated at 12V.