Abstract: An enteral fluid infusion system wherein fluid is pumped through a conduit from a fluid supply source to a patient by a rotary peristaltic pump operating in an intermittent duty cycle mode which includes a free flow detector. The free flow detector includes a sensor for the operation of the peristaltic pump, as for example by the rotation of the rotor and/or motor; a sensor for the flow of fluid in the conduit. The free flow detector compares the sensed operation of the pump with the sensed flow against predetermined criteria. During operation of the fluid infusion system, if flow is sensed when the pump is not operating, as determined by the fact that no rotation is occurring, an alarm will be initiated to indicate that a free flow condition exists.