NEC-Electric Safety Program

Codes and Standards

The scope of this study includes short-circuit study evaluation. Although code violations are made apparent where possible, the facility should be assessed for specific NEC codes and other regulatory standards as an independent study.

NEC - Electric Safety Standard

NEC-2017 Arcticle 110.24 (A) titled
"Field Markingstates:


“Service equipment at other than dwelling units shall be legibly marked in the field with the maximum available fault current. The field marking(s) shall include the date the fault-current calculation was performed and be of sufficient durability to withstand the environment involved. The calculation shall be documented and made available to those authorized to design, install, inspect, maintain, or operate the system.”


NEC - Electric Safety Standard

NEC-2017 Arcticle 110.24 (B) titled
"Modification" states:


“Service equipment at other than dwelling units shall be legibly marked in the field with the maximum available fault current. The field marking(s) shall include the date the fault-current calculation was performed and be of sufficient durability to withstand the environment involved. The calculation shall be documented and made available to those authorized to design, install, inspect, maintain, or operate the system.”


NEC - Electric Safety Standard

NEC-2017 Arcticle 110.10 titled "Circuit Impedance,  Short Circuit Current Ratings, and other Characteristicsstates:


"The overcurrent protective devices, the total impedance, the equipment short-circuit current ratings, and other characteristics of the circuit to be protected shall be selected and coordinated to permit the circuit protective devices used to clear a fault to do so without extensive damage to the electrical equipment of the circuit.”


NEC - Electric Safety Standard

NEC-2017 Arcticle 110.9 titled "Interrupting Rating" states:


“Equipment intended to interrupt current at fault levels shall have an interrupting rating at nominal circuit voltage at least equal to the current that is available at the line terminals of the equipment. Equipment intended to interrupt current at other than fault levels shall have an interrupting rating at nominal circuit voltage at least equal to the current that must be interrupted.”