Final answer:
The question pertains to electrical engineering and the sizing of main bonding jumpers and system bonding jumpers. The provided reference, however, is related to enthalpy calculations in chemistry based on bond energies. The actual electrical code information would be found in electrical engineering resources, not in chemistry references.
Step-by-step explanation:
The question refers to the section 250.28 Main Bonding Jumper and System Bonding Jumper. (D) Size. (3) Separately Derived System with More Than One Enclosure of an electrical code, which specifies requirements for the sizing of main bonding jumpers and system bonding jumpers in electrical systems, especially for situations involving a separately derived system with more than one enclosure.
The provided information appears to relate to enthalpy calculations in Chemistry, linked to the energy changes during bond formation and bond breaking in chemical reactions. For example, the expression bonds broken minus bonds formed, alongside values such as 25 J, 75 J, and so on, seems to suggest the evaluation of reaction enthalpy based on bond energies, indicated by the symbol D. While these values do provide an understanding of enthalpy, they do not directly relate to the electrical code in question.
Therefore, to properly address the electrical code's content, one would need to refer to specific electrical engineering texts or the National Electrical Code documentation itself, rather than the enthalpy calculation concepts from Chemistry.