Q. Regarding many areas in hilchos Shabbos there is a difference if the melocha is from the Torah or derabanan: amira lakum, maseh Shabbos etc. What is the status of electricity regarding such issues?

A. When electricity is used to make a filament glow and give light or to provide heat as in stove burners or the like, most Poskim maintain that one transgresses the biblical prohibition of ma’avir (kindling – Achiezer 3: 60, 4: 7, Beis Yitzchok Y.D. 120 – 125, Minchas Shlomo 12, Meorei Haeish, Yesodey Yeshurun – Maavir, et.al.). Others call it mevashel – cooking (Chazon Ish 50: 9). A few maintain that it is only rabbinical since even when the metal gets heated and burns or when it glows, it does not get consumed.
When no light or heat is produced, some still maintain that the Torah prohibitions of bonneh (building) apply, since the closed electrical circuit binds together the different components of the appliance or electrical device (Chazon Ish 50: 9). Another biblical prohibition considered is tikun mono (finishing the making of a utensil), since without the electrical power being applied the devise is non-functional and useless. However, other Poskim are lenient and may permit the use of electrical circuitry in cases of need such as in hearing aids or similar (Igrois Moishe O.H. 4: 85, see next question). Some Poskim (Beis Yitzchok Y.D. 1: 2) also assert that one transgresses on the rabbinical proscription of molid (bringing about any creative change in an item).
Horav Shlomo Miller’s Shlit”a opinion is that in most cases activating any electrical circuitry, even when no heat or light is created, besides the rabbinical prohibition of molid, should be considered at least as a sofek deuraisso, or doubtful Torah prohibition because of the tikun mono involved.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a