A fault-tolerant maintenance bus protocol and method for using the same enables communication between a command module located on a parent maintenance bus and a plurality of subsystem components joined together on a child maintenance bus. The power source is capable of receiving any input voltage over a wide range of input voltages and includes an input rectifier that rectifies the ac input into a dc signal. A device is also provided for securing or locking the movable part to the stationary part when a desired grip configuration has been achieved.