Final Representation_WSMR_ISF DC Power.pdf

This is a technical specification document for -48VDC infrastructure installation within a data center or critical facility system.

The document details requirements for providing -48VDC power distribution infrastructure, including conduit, conductors, and wire routing. Coordination between the facility user and IMD equipment vendor VERTIV was required to design the system and establish infrastructure obligations. The specification includes a comprehensive system diagram approved by both the user and vendor, illustrating the complete -48VDC power distribution architecture with multiple distribution bars, shunting DC circuit breakers for user-required -48V Emergency Power Off (EPO) functionality, and connections to remote equipment. The diagram demonstrates the integration of additional shunting DC CBs necessary to implement the EPO feature, which is not provided by the manufacturer as standard capability. DC cable wire sizing must be calculated according to column 1 of table 393.22(B)(1) in the National Electrical Code (NEC). The specification also references earlier redundancy requirements, including provisions for critical HVAC fan and pump equipment for 100% redundant systems at 50% capacity allocation.