Converter In-Rush Thermistors etc, UPDATE -4
UPDATE on 17 Nov, Update 2 on 22 Nov, Update 3 on 16 Jan 14, Update 4 on 19 Oct 14. --------------- In a recent thread there was mention of how you can wreck your gizmo (in my case a converter) ...
Forum Discussion
The equation on 7/10 is not correct.
Should be:
Imax = Power / (efficiency * Vmin)
Imax = 2 kVA / (0.7 * 90V) = 31.7A
They use minimum input voltage (90V) to get maximum input current. This is the worst case scenario.
I don't know your converter spec. It could be something like 100A @ 15V & efficiency = 80%.
Maximum input current is:
Imax = 100A * 15V /(0.8 * 108V)
Imax = 17A
A kill-a-watt meter would come in handy to see actual numbers.
"Can I pretend I have the same transformer they used with 2000VA if mine is indeed around 1800?"
No, totally different designs. Your transformer operates at about 15kHz, the one in the example operates at 60Hz. Also, thermistor resistance is not based on the size of the capacitor bank. There is no correlation between the two. The thermistor minimum energy rating is based on the size of the capacitors.
Sal
Should be:
Imax = Power / (efficiency * Vmin)
Imax = 2 kVA / (0.7 * 90V) = 31.7A
They use minimum input voltage (90V) to get maximum input current. This is the worst case scenario.
I don't know your converter spec. It could be something like 100A @ 15V & efficiency = 80%.
Maximum input current is:
Imax = 100A * 15V /(0.8 * 108V)
Imax = 17A
A kill-a-watt meter would come in handy to see actual numbers.
"Can I pretend I have the same transformer they used with 2000VA if mine is indeed around 1800?"
No, totally different designs. Your transformer operates at about 15kHz, the one in the example operates at 60Hz. Also, thermistor resistance is not based on the size of the capacitor bank. There is no correlation between the two. The thermistor minimum energy rating is based on the size of the capacitors.
Sal
