Answer / g.shanmugam

Battery back up time=Battery current at full load/Battery Ah

Answer / guest

As a thump rule,if we need 1 hrs backup from the 1 KVA UPS
12V/130AH is Required,For Example,10 KVA ON-Line
UPS,Battery-12V/65AH,26 nos.

BAck-up Time=Ah of the Battery*Total no of the
Battery/Output KVA*130
BAck-up Time=65*26/10*130
BAck-up Time=1.3
BAck-up Time=60~70 Mins(Approx)

Answer / r.gopalakrishnan

SEE SUPPOSE IF I NEED 740 WATTS USAGE BACK UP TIME UP TO 3
HOURS, THAN I CAN CALCULATE LIKE THIS(EXAMPLE 1
PC@350WATTS,3 FANS@80X3=240WATTS& 3TUBE LIGHTS
@(40+10CHOKE)=50=150WATTS)TOTAL=740 WATTS REQUIRE,= 740
DIVIDED BY 12 V=(61.666667)>61 Ah per hourx3
ours=183Ahbattery,(180Ah Battery).now you have selected
battery & than select a UPS/inverter that is you can only
get 80% of your UPS/inverter.Ex;1000 watts Ups/inverter.that
will be always safe for you & ever.thanks.R.GOPALAKRISHNAN.

Answer / sss

UPS Backup=Battery Voltage*Battery Ah/Load (watt)

Answer / subir kumar manna

UPS BACKUP TIME= NO OF BATTERY X AH OF BATTERY /OUTPUT KVA
X130

Answer / parameshwara.s

Tell me on a 5 KVA UPS with 12 Batteries of 65 AH how many
hours of backup will I have on full load.

Answer / n.muthukumar

ups backup time=battery AH*battery efficiency*no.of
batteries/ups capacity in kva*130*output power factor

for example:65*0.9*10/5*130*0.8=1.125

approximately:1hr 15min

Answer / claudiu

You can calculate the max time to use a UPS with this
formula

T max = efectiv energi / average power of the energy

that min

T max = 1377 (this is a constant, it's so big because it's
calculate in seconds)* capacity of batery in volts 12V *
capacity of batery in amper's 10Ah or other valu * number
of moduls (number of bateris to use) / how mutch power you
want to consum in W

for exemple

I have 8 baterys with 12V and 10Ah and I want to standup a
computer with 300 W consum

so
1377*8*10*12/300 = 4406.4 seconds that min 4406.4/3600 =
1.2h

sorry for my english

best regards,
Claudiu from ROMANIA

The sours is
http://en.wikipedia.org/wiki/Uninterruptible_power_supply

Answer / asela

nomber of battery * battery voltage * each battery AHR
(130AHR total/ nomber of battery)130/260* efficiancy 90
PERCENT/ tatal VR.

26*12*5*0.9/1000
1 HR AND 4 MINUTES

Answer / yogesh

UPS backup time= Ah of battery * no of battery/output kva * 130

i have been tasked with a design of protection, metering and control(PMC) relay panel extension to accommodate all PMC relays.There is an already existing panel where this one will be built.What are the design aspects for this kind of project? thank you.

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