what is the formula for backup time of online ups?



what is the formula for backup time of online ups?..

Answer / sudhakar g

Hi,

First you want to know how much required for your company or home anything.....suppose we can take 1200w load we required then take 1.5kva inverter
kw=kva x p.f
1200=kva x 0.8
kva=1500

number of SMF batteries=N=6
Voltage of each DC battery = V = 12 V
Ampere-hour of each battery (AH) = X1)
Suppose incase of 2hours usage T=2hours
Volt-Ampere = (N * V * X*EFFicency)/ T
1500 = (6*12*X*0.9)/2
1500 = 33X
X= 43 AH
or else
Time=(number of batteries*voltage of battery*AH)/VA
T=(6*12*43*0.9)/1500
T=1.9hrs
Nearly 100minutes

Is This Answer Correct ?    7 Yes 1 No

Post New Answer

More Electrical Engineering Interview Questions

how we have to calculate the short circuit current for 33/11kv 2mva, 7.5% Z, Transformer primary side breaker and secondary side breaker short circuit current for both sides?.

5 Answers  


In a single phase converter, the no. of SCR conducting during overlap? a.1 b.2 c. 3 d. 4

3 Answers  


How the value of KVAR of capacitor bank used in switchgears calculated??

2 Answers  


IN electrical field, WHAT ALL THINGS THE CUSTOMER WILL ASK WHILE ORDERING FOR LT PANEL (ALL TYPES OF LOW TENSION PANEL)

0 Answers   L&T,


How to calculate ht side cable of 630 kva oil cooled outdoor transformer?

1 Answers  






How the earth fault relay works please explain?????????

2 Answers  


Radio Carbon dating is used in a) find diseases b) find the age of relics c) find the carbon content in the atmosphere d) none of these

2 Answers  


Is it possible to run HT motor through LT VFD (LT VFD supply given to Transformer LT side and transformer HT side connected to motor)

1 Answers  


What is the basic working principle of Tri vector meter?

5 Answers   TCS,


Why let through energy not considered for ACB breaker while cable sizing?

0 Answers  


why doesnt the back emf hold the speed of unloaded series motor?

1 Answers  


what is the working difference b/w softstarter and Variable frequency drive ?

6 Answers   Parle,


Categories
  • Civil Engineering Interview Questions Civil Engineering (5085)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4451)
  • Electrical Engineering Interview Questions Electrical Engineering (16632)
  • Electronics Communications Interview Questions Electronics Communications (3918)
  • Chemical Engineering Interview Questions Chemical Engineering (1095)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (239)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (259)
  • Instrumentation Interview Questions Instrumentation (3014)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (124)
  • Power Plant Engineering Interview Questions Power Plant Engineering (172)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (25)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1379)