NFPA 70E 2024 (Article 205.3) mandates “A single line diagram, where provided for the electrical system, shall be maintained in a legible condition and shall be kept current”. These drawings serve as an essential reference when adding new elements to your power distribution, upgrading equipment or trouble-shooting power flow.
When conducting an arc flash risk assessment, a single line diagram is used to model power flow of the electrical distribution system. The single line diagram should be updated in the event of any modifications to your electrical system.