Why can you read almost 2-3A AC current via multimeter on utility input of sPF Series inverter
Some clients are curious about the phenomenon, here is the explanation.
Phenomenon
When clients measure utility input current via multimeter AC current position, they will get 2-3 A AC current. And they will think why the inverter consumes much power. They use fomula :
P = UIcosφ
P= 230v* 3A* 0.9( they think PF is 08-0.9 like grid)
as we know, In the datasheet, it claims almost 60W on inverter self-consumption. That’s why so many clients are confused.
Reason
The formula above is correct, the problem is about cosφ ( Power Factor), we know that it is almost 0.8-0.9 for familiy applicances. But to inverer, device, it is different, inside inverter, there are so many capacitors like below:
PF value in the situation is pretty low, like 0.1-0.2. So we can caculate it based on above formula
P = UIcosφ
P= 230v* 3A* 0.1
it equals almost 60W