I want to calculate the backup duration of 1 KVA UPS in fully charged condition when there is load of 200 watts to it. Any body can please tell me the formula for it ? Thanks in advance.
2007-09-17 21:23:11 · 8 answers · asked by TheHonest 1 in Science & Mathematics ➔ Engineering
It will require the voltage value of the charging battery so that upto what time it will survive can be known.
The VA rating for a power source is called "Volt-Amperes". It is a measure of power because Power = Volts*Amperes. AC power sources are denoted in this way.
This is an estimate.
If the wall power supply has a nominal voltage of 9VAC and with a 15VA rating then the current equals 15/9=1.66 amperes. The 9 volt battery in your system typically can supply 500milliamps for 1 hr. At the worst case, with the battery powering your system at 9V and 500milliamps, the system will last for only 1 Hr. Let's use this case as the baseline. A 1000VA supply is capable of suppling 9volts and 110 amperes for 1 Hr. This is scalable. It can supply 1 ampere for 1000 Hrs or 0.5 amperes(500milliamperes) for 2000 Hrs. The system only draws the current that it needs.
I hope this points you in the right direction.
2007-09-18 00:54:17 · answer #1 · answered by sb 7 · 0⤊ 0⤋
Kva Vs Watt
2016-12-12 18:57:35 · answer #2 · answered by Anonymous · 0⤊ 0⤋
The relationship that you need is
Watts = KVA * Power Factor
The power factor is defined to be the cosine of the phase angle between the voltage and the current, and the KVA rating is the product of teh RMS voltage times the RMS amperage without regard to the power factor. Watts are 'real' power, KVA is 'apparent' power. If your load isn't too terribly reactive (looking like a large capacitor or inductor) then the power factor is probably close enough to 1 that the KVA rating is about the same as the KW rating.
HTH
Doug
2007-09-17 21:50:17 · answer #3 · answered by doug_donaghue 7 · 4⤊ 0⤋
They're the same. Watts = Volts x Amps KVA = KiloVoltAmps KW = Kilowatts
2016-03-13 04:44:19 · answer #4 · answered by Anonymous · 0⤊ 0⤋
POWER (WATTS) = VOLTS x AMPERES
Generally: P=IE P= Power(WATTS), I = Current(AMPS) and E = Voltage. So: I = P/E and E = P/I So:
1 watt = 1 volt X 1 ampere
Similarly 1KVA = 1KW
so 200 W = 200 VA
2007-09-18 00:30:47 · answer #5 · answered by Sweety 1 · 0⤊ 0⤋
power is V*I or volt * ampers ie 1 watt = 1 volt * 1 amper
KVA is kilo volt amper ie volt ampere*1000 or 1000watt .
For the load of 200watt , the ups should work for 5hours .
200watt load consumes 200watt in one hour so in 5 hours it will take 1000watts or 1KVA .
2007-09-17 21:34:54 · answer #6 · answered by Anonymous · 1⤊ 0⤋
Energy (watt) = Volts x Current.
http://www.newton.dep.anl.gov/askasci/phy00/phy00205.htm
2007-09-17 21:33:52 · answer #7 · answered by ThunderCyclon 3 · 0⤊ 0⤋
1W = 1VA
1000W = 1kVA
2007-09-18 00:01:42 · answer #8 · answered by Marcus Paul 3 · 0⤊ 0⤋