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1. Acceptance of Terms

By accessing or using Premium Electrical Calculators ("the Site"), you agree to be bound by these Terms and Conditions. If you do not agree, you must exit the Site immediately.

2. For Reference Only

All calculators are for general reference and educational purposes only. Never use results as the sole basis for any electrical installation or design decision.

3. No Warranty on Accuracy

Premium Electrical Calculators makes no representations or warranties regarding completeness, accuracy, or reliability of results. Always verify against current NEC and local codes.

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To the fullest extent permitted by law, Premium Electrical Calculators shall not be liable for any damages arising from use of this site or its tools.

5. NEC Compliance Notice

Calculations are based on NEC standards at time of development. Verify compliance with the current adopted edition of the NEC and all local amendments.

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7. User Responsibility

You assume full responsibility for how you use results. All electrical work must be performed by a qualified, licensed electrician.

8. Changes to Terms

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9. Governing Law

These terms are governed by the laws of the State of Arkansas.

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Circuit Breaker/Fuse Size Calculator

Calculate the correct OCPD size for general, motor, HVAC, and welder loads per NEC. Select your load type and enter your circuit details.

Helpful Notes:

OCPD Sizing Rules

General loads are sized at 125% of continuous load per NEC 210.20.

Motor loads use NEC 430.52 — inverse time breakers are sized at 250% of FLA; time-delay fuses at 175%.

Standard OCPD Sizes

Per NEC 240.6(A), standard breaker/fuse sizes are: 15, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 350, 400, 450, 500A. This calculator rounds up to the next standard size.

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