Service load calculations wrapper
Why you care (60 seconds)
Service load calculations determine service size and equipment ratings. Using the wrong method leads to oversized or undersized services.
Where people lose time
- Mixing standard and optional calculation methods.
- Applying demand factors incorrectly.
- Forgetting to include fixed appliances or HVAC loads.
This is
The rule in plain language
Service load calculations use defined methods to determine demand loads and select service ratings accordingly.
When it applies
Any time sizing or verifying a service or main equipment based on load.
What you must do (checklist)
- Choose the correct calculation method for the project.
- Apply demand factors as required.
- Include all required load categories.
- Document the calculation steps and assumptions.
Quick examples
- Optional calculation methods have specific conditions.
- HVAC loads can dominate service calculations.
This is not
Common misreads
- Treating a quick rule-of-thumb as a compliant calculation.
- Omitting fixed appliances from the load list.
What it doesn't cover
- Utility company service requirements.
- Detailed load studies for commercial campuses.
False friends
- Connected load totals are not always the service calculation result.
Exceptions & edge cases
- Some occupancies require different calculation methods.
- Certain load categories have special demand factors.
Cross-references (NEC map)
- Primary: 220.42, 220.82
- Secondary: 220.40
Exam traps
- Mixing optional and standard methods incorrectly.
- Missing required loads in the calculation.
Field notes
- Keep calculation worksheets for plan review and inspection.
- Coordinate appliance schedules early to avoid surprises.
AHJ / Local amendments notes (placeholder)
- Add local amendments or interpretations here.
Revision notes
- Draft wrapper created for service load calculation fundamentals.