Section 240-92(b) titled Transformer Secondary Conductors of Separately Derived Systems is divided into three sections that shall be complied with:

• Short-Circuit and Ground-Fault Protection for conductors and
• Contains 3 Rules
• Overload protection for conductors.
• Contains 4 Rules
• Physical Protection

The first section has three rules and the second section has four rules. One rule in each section must be followed. This provides twelve combinations of designs for protecting transformer secondary conductors of separately derived systems. The above diagram illustrates one such combination.
A requirement to suitably protect the secondary conductors from physical damage applies to all combinations.

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