Mack said:
Thank you all for replying - Its a heater which is pure resistance. Can
anyone tell me the formula for working this out please?, if their is a
'simple' rule of thumb, that will do nicely.
Cheers.
Mack.
The term 'VA' comes from 'Volt-Ampere' which is one rating of transformers.
It means, literally Volts times Amps.
It is useful for transformer ratings because the same number applies to
either the primary or secondary. If you have a 240V to 110 V step down
transformer that is rated 100 VA, then...
Secondary...
100 VA = 110V X 0.909 A
Primary...
100VA = 240V X 0.4166A
The power in Watts is from a formula...
P = V X A X pf
pf = Power factor. For resistive loads it is 1.00, so the power in watts is
equal to Volts X Amps (which is 'VA').
100VA with a resistive load is 100 Watts
daestrom