Help Calculating input power and amp draw?
Favorites|Homepage
Subscriptions | sitemap
HOME > > Help Calculating input power and amp draw?

Help Calculating input power and amp draw?

[From: ] [author: ] [Date: 17-03-31] [Hit: ]
but thats all we can reliably do. It says VA because you cant just calculate power the same as a resistant load. Inductive reactance increases with increases in frequency, and there are other unknown factors, like if there is a capacitor, and its size,......
Help Calculating input power and amp draw?
Hello I am trying to figure out what the amp draw is of a light.

It says 1050VA at 230V 50Hz.

What would the amps it draws be at 208V 60Hz?

and Yes It can run at 208 at 60 Hurtz
-------------------------------------------------------

answers:
dtstellwagen say: It's going to be a little higher, we can guess just under 5 amps, but that's all we can reliably do.

It says VA because you can't just calculate power the same as a resistant load. Inductive reactance increases with increases in frequency, and there are other unknown factors, like if there is a capacitor, and it's size, we don't know if the transformer is connected to the same tap, a longer coil will have increased inductance, and the power factor of the transformer.

Just way too much to calculate with any usable reliability. Best to try to dig up some literature from the manufacturer for the numbers.
-
Fazaldin A say: Given that: 1050VA at 230V 50Hz.
So,
Current, Irms = 1050 / 230 = 4.565 Amps.
-
Lee26Caloo秦君子蘭 say: AT 230V, LAMP CONSUMES 4.57A
AT 208V, LAMP CONSUMES 4.13A
-
Mr. Un-couth say: At 230V;
Amps = 1050VA/230V = 4.565217391 A


At 208V;
Amps ~ (208/230)*(4.565217391A) = 4.128544423 Amps
Input VA = (208V)*(4.128544423A) = 858.7372401 Volt-Amps

Note; Can not calculate input power (Watts) without power factor or phase angle
-
say: If you are saying it can work identically at 208V., then its power must be equal (as would its hot resistance and brilliance be).
(1050/208) = 5.048A. RMS.
Otherwise, cannot be done.
It's HERTZ, frequency would be immaterial.
-
Joe say: I'd normally agree with Derfram, but I think he's missed something.

This is a fixture with a ballast, or transformer, right? There's a different pigtail lead, or terminal, that you use when you're connecting 208 Volts, vs. 230 Volts?

If so, it's going into a different primary winding (tap on the primary), and the power consumption should remain constant at either voltage. If you're using the 208 Volt tap, the current should be about 1050/208 = 5.05 Amps.

If you're not sure, provide the greater capacity. This sort of fixture usually pulls an inrush surge at startup.
-
derfram say: Normally a lamp (light) would be rated in watts, not volt-amps. VA is generally a spec on a reactive load. In any case:

I = P/E = 1050/230 = 4.57 amps.


At 208 volts, the draw would be a little less. Perhaps 4 - 4.24 amps. It's not a direct conversion because the resistance of a lamp changes significantly with applied voltage.

Frequency should not be an issue unless this is actually some electronic light control assembly rather than a simple lamp.
-

1
keywords: power,and,input,Calculating,Help,draw,amp,Help Calculating input power and amp draw?
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .