The combined effect of these various actions was an extremely unstable reactor configuration. Nearly all of the 211 control rods had been extracted manually, including all but 18 of the "fail-safe" manually operated rods of the minimum 28 that were supposed to remain fully inserted to control the reactor even in the event of a loss of coolant. While the emergency scram system that would insert all control rods to shut down the reactor could still be activated manually (through the "AZ-5" switch), the automated system that would ordinarily do the same had been mostly disabled to maintain the power level, and many other automated and even passive safety features of the reactor had been bypassed.