Restore the electrically driven portion of compatible HES access-control hardware with a 24 V DC solenoid assembly configured as 55 fail. This component-level assembly addresses installations where the solenoid requires replacement rather than a complete locking device. Its 24 V DC electrical requirement makes control-power matching a primary installation check. Part number 31-0993-1-IP identifies the HES solenoid assembly supplied in the 55 fail configuration. Electrical selection is explicit: the assembly operates from 24 V DC. Match the connected lock-control output to that voltage before installation; an incorrect supply can prevent expected actuation and may damage the component. No current draw or connector specification should be assumed when replacing an installed assembly. The 55 fail designation should be matched exactly to the markings on the installed hardware. It identifies a configuration within the solenoid assembly range, not a general description of every HES locking product. Compare the existing solenoid, mounting arrangement, and connected hardware before fitting the assembly. This check is especially important where similar physical-security devices share an installation location but use different electrical or mechanical configurations.