[Avodah] The Heter of Davar She Eino Mischavin by a Star-K

[D&E-H Bannett]

Re:  <<when we open refrigerator doors. It is a Davar 
SheEino Mischavin and not a Psik Reisha. The fridge motor 
does not automatically go on if we don't hold the door open 
too long. The same is true for an oven WRT its heating 
coils. The big difference is how long the door must remain 
open for it to be a Psik Reisha. By a Fridge, it is a lot 
longer than by an oven. Some say that an oven's "window of 
opportunity" for it not to be a Psik Reisha is almost nil 
making it impractical to apply the " Fridge door heter"  to 
an oven. I believe it remains an open Shiala.>>

Unless you consider causing a motor to rotate to be its 
boneh, how can you compare the two cases?  Does the Torah 
state "Lo t'va'aru eish"  or does it say "Lo t'sovev 
manoa'"?

David