When this service helps
Electrical protection studies examine how the distribution system responds to faults and how protective devices interact. They can be important when service equipment changes, new distribution is added, or critical building loads require a coordinated protection strategy. The study scope should identify which parts of the system and which operating conditions are being evaluated.
What the engineering scope addresses
Short-circuit analysis evaluates available fault current and applicable equipment ratings. Selective coordination assesses the relationship between upstream and downstream protective devices using the relevant device characteristics. Where included, arc-flash analysis considers incident energy and associated labeling recommendations based on a documented system model and agreed methodology.
Planning the next step
Accurate input data matters. Device manufacturer and model, fuse types, breaker settings, conductor lengths and sizes, transformers, and available utility fault information can affect the results. The report should identify assumptions and required field verification. A study or label does not replace an employer's electrical safety program, safe work practices, or the need for appropriately qualified personnel.
Potential deliverables
- Short-circuit calculations and equipment-duty checks
- Selective coordination studies and time-current curves
- Arc-flash analysis and labeling recommendations where scoped
The proposal confirms the exact deliverables and any site visits, follow-up review, filing support, or construction services included.
What to prepare
- Current one-line diagram and equipment inventory
- Protective-device types, ratings, and settings
- Feeder sizes, lengths, and transformer information
- Available utility fault-current information
Share what is available and identify records that are missing. We can help define the initial engineering scope around the information and access your project has.
Related guidance
DOB Electrical Plan Review: Documents to Prepare for an NYC Project
Our resource library includes practical checklists and links to official NYC documents.