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Watts, volt-amperes, and power factorIn a DC circuit watts and volt-amperes are the same, as 1W = 1V x 1A, but in an AC circuit they have different meanings.

Volt-amperes (VA) are used as a measurement of "apparent power" delivered to a load, calculated as the RMS voltage times the average current measured at the input to the device. Wattage is used to express true power dissipation in an AC circuit, calculated by integrating the product of current through the load and voltage over time. These may sound like they would be the same, but the characteristics of AC circuits can be such that some of the current flowing into the circuit is stored and then discharged back into the power line, without actually flowing through the circuit.

An AC circuit has a characteristic called the power factor (PF) that determines the relationship between true and apparent power; i.e., the conversion between volt-amperes and wattage. It varies from 0.0 to 1.0, but proper designs should have a PF close to 1.0, so frequently there is little difference between watts and VA. The wattage will always be lower than or equal to the volt-amperes. In the case of devices with significantly low power factors (such as fan motors, which may be around 0.65 when running and as low as 0.1 when first turned on), the wattage may be significantly lower than the volt-amperes, which can be a concern when using watt ratings: One might expect a 960-watt device to draw 8 amps at 120V, but if it has a PF of 0.65 it would actually draw 12.3 amps. This could be a problem if it is plugged into an outlet on a 10-amp breaker!

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How many amps would a 15watt radio draw in the transmit mode with 12 volt being supplied to the radio?

1.25 amps


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Answer Generators usually always go by watts. To figure this all you do is take(volts x Amps) = watts. You know the volts (220) then look on the pump for the amp rating and then multiply them and you will have your watts. Then get a generator that is rated for this amount for continuos operation not peak watts. Hope this helps.


What is stronger a 1 amp battery charger or a 9v battery?

You cannot compare these two totally different things. As far as amperage the charger puts out more amps if it is an auto battery charger and also puts out 12 volts. If you are talking about a 9 volt battery charger then the battery may or may not be more powerful, it depends on how many mii-amps the charger is putting out.


Are there 100A available on both bars of a 100A panel in a home and for instance can you draw 75A on each bar?

The amp rating of a panel is based on the size of materials used (the bars, etc). You can pull 400 amps through your panel (provided a 400amp breaker was in place); but it would probably melt down very quickly. Basically you have 100 amps total to play with: be it from two 50amp breakers or 30 subpanels pulling 3 amps. :D You just can't pull more than 100amps at one time or the main will trip. The 100 amps is a rating for each bar. If your panel has a 100 amp double pole breaker, then you can use up to 100 amps on each pole. You really shouldn't draw more than 80 amps continuously. But you can count on having that 160 amps avilable if all your loads use only one hot leg of the panel (120 volt loads instead of 240).


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Related Questions

How many amps are in 40 volt amps?

Multiply the vots by the amps to find the volt-amps. Or divide the volt-amps by the voltage to find the amps.


How do you convert 208 volt amps to 480 volt amps?

Add another leg of 120 to a three pole breaker.


How many volt amps in 12 volt battery?

Depends on the battery. It is listed on the battery as Cold Cranking Amps (CCA).


What is the difference between amps and volt-amps?

Amps (A) measure electrical current flow, while volt-amps (VA) measure apparent power in an electrical circuit, which is the combination of both real power (measured in watts) and reactive power. Essentially, amps refer to current, while volt-amps refer to total power.


What is the amps of a 7.5 hp 480 volt 3 phase?

88 amps


Is it true that volt amps are the same as watts?

No, volt-amps (VA) and watts (W) are not the same. Watts measure real power in an electrical circuit, while volt-amps represent the apparent power, which includes both real power and reactive power.


How do you calculate volts with volt amperes?

Divide the circuits amperage into the volt amps and you will get the voltage.


Convert Volt-amps to total amps?

To find your amps, divide your volt amps listed by the voltage you are using (and the device is rated for).Power in watts = Volts X AmpsVolts equals amps X resistance. All of these formulas can be transposed to find the missing element.If something is listed as 360 Volt amps and the voltage used is 120 volts it draws 3amps. So if the same device was used on a 240 volt circuit it would draw 1.5 amps. the power company charges for power (watts) so the volt amps are listed on the device and costs you the same regardless of the voltage used.If the same thing was designed for 12 volts it would draw 30 ampsThe current in amps is equal to the apparent power in volt-amps divided by the voltage in volts:A = VA / V


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No you cannot house amps use 120 volt ac car amps use 12 volt dc


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A transformer's capacity is rated in volt amperes(V.A). This is the product of the secondary winding's current rating and voltage rating.


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The formula for amps is I = W/E. Amps = 40/240 = .17 primary amperage. For the secondary amperage I = W/E. Amps = 40/24 = 1.7 amps.


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9.6va (or watts) divided by 12Volts = 0.8 amps