hi,
I was trying to run my table fun on an UPS (660 VA, with full load time
10 mins). My table fan has a rating of 80VA. On searching on net for
calculation I came up with the following figu

time of run = 660/80 * 1.5 * 10 = 123.75 mins

The figure 1.5, to be applied if ( UPS rating / FAN rating ) = 660/80
(this case) is grtr than 3 else multiplying factor = 1.3, This was
from one of the pages, can someone reason out this.

I am not from an electrical background I was able to come up with this
figure after some googling.

but I find my UPS supporting my fan on an average of 1/2 hr. Can
someone verify this and tell me wat am I missing .