A robot must protect its own existence as long as such protection does not conflict with the First or Second Laws.
More from Isaac Asimov
A robot must obey the orders given it by human beings except where such orders would conflict with the First Law.
Permalink to quote #24 A robot may not injure humanity, or, through inaction, allow humanity to come to harm.
Permalink to quote #26 A robot may not injure a human being, or, through inaction, allow a human being to come to harm.
Permalink to quote #23