What does everyone use as far as amps in a variac to cut out a 24" to 32" wide board?

I work in metric, but here is my way of working:

EPS works great at 40W/m which is about 1W/inch so that makes a total of 24W or 32W power needed. The amount of amps is completely dependant on the wire you use.

If your wire is 3ohms/m or 0.076ohm/inch, you can caculate the required voltage and current

sqrt((1 (W / inch)) / (0.076 (ohm / inch))) =

3.62738125 amperes

(0.076 (ohm / inch)) * (3.62738125 amperes) =

0.275680975 V / inch

With XPS I went up to 60W/m if I’m not mistaken.

Anyway, just substitute the numbers in the formula above and you’ll get the numbers.

But for selecting a variac, you should look at the input power (Watts) and not the output current, as the max current is different for every voltage it outputs. Only the Power is equal on both the input and output (assuming 100% efficiency).

**So with a 60W variac, you’ll be fine.**

Thanks for the info. After doing the equation, I realize I have some options. Thank you!