Service Entrance Calculator
Calculate electrical service entrance requirements for residential and commercial buildings. Determine wire size, conduit size, and service panel requirements based on load calculations.
Step 1: Electrical Load
Understanding Service Entrance
Service entrance refers to the conductors and equipment that deliver electrical power from the utility to the building’s main distribution panel. Proper sizing is critical for safety and code compliance.
Step 2: Calculation Options
Electrical Codes
NEC Article 230: Covers service entrance requirements
Continuous Load: Multiply by 125% for loads lasting 3+ hours
Voltage Drop: Should not exceed 3% for branch circuits, 5% total
Service Entrance Calculation Results
Recommended Service Size
Wire Size Comparison (Copper @ 75°C)
| AWG/kcmil | Ampacity | Max Service | Ohms/1000ft | Common Use |
|---|
Electrical Code References (NEC 2023)
Article 230 – Services
230.42: Minimum size based on calculated load
230.79: Rating of service disconnect
230.90: Overcurrent protection requirements
Service conductors must be sized to carry the load with proper overcurrent protection.
Article 310 – Conductors
310.16: Ampacity tables for conductors
310.15(B): Temperature correction factors
310.15(C): Adjustment factors for multiple conductors
Conductors must be sized to prevent overheating under all conditions.
Article 250 – Grounding
250.66: Size of grounding electrode conductor
250.122: Size of equipment grounding conductor
Proper grounding is essential for safety and fault current path.
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