A medical pump includes a chassis having a fixed seat, and a main carriage having a carriage footing for receiving a fluid delivery device and restricting its movement. An actuator automatically moves the main carriage between open and closed positions to engage the fluid delivery device to the seat. The seat establishes the position of both the main carriage and fluid delivery device in the closed position. The actuator is connected to the main carriage by a rear carriage assembly having a manual release element for disengaging the actuator from rear carriage assembly and thereby from the main carriage. A processing unit detects jam conditions by processing carriage position data and electrical load data from the actuator.