I'm not sure if this is the best place to ask electronics engineering 
type questions; so if anyone knows of an engineering-related forum, 
please let me know... 

I am in the process of designing a power board to military specs, and 
one of the requirements is "2500V isolation between primary and 
secondary". Using the formula that says 0.12 mils/volt, I am looking 
at a 300mil clearance wherever appropriate, right? 

One of the components in the design is an opto-isolator in a DIP8 
package, and the data sheet guarantees 3000V insulation between 
primary and secondary. Since it is packaged in a DIP, and I am 
required to use 65 mil pads, I am only left with 235 mils between 
primary and secondary, which works out to (235/0.12) 1958.3 volts.

Am I misinterpreting the requirements?

Is their 3000V claim based on a different dielectric or something 
internal to the component? If so, how is that meaningful knowing the 
DIP package must be mounted to something with a lower value?

Is the 0.12 mils/volt spec over-estimated to be on the "safe" side?

Are the terms "insulation" and "isolation" interchangeable?

Can I use this component (and/or) Am I splitting hairs?

thanks in advance,					Jack