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Motor Protection Sizer

Overload relay setting & trip class (NEC 430.32 / IEC 60947-4-1), contactor sizing by AC-3/AC-4 utilization category, and ground-fault pickup guidance by system grounding type. Fully free — no subscriber gate. The ground-fault section is typical- practice guidance, not a substitute for a coordination study.

AAJappsEngineering Calculation Report

Motor Protection Sizer

NEC 430.32, IEC 60947-4-1, IEC 60034-1

Generated

For preliminary engineering use only — always verify results against project-specific standards and a qualified engineer's review before use in a real design.

Motor & overload relay

A
s

Contactor

Ground-fault protection

Overload relay

Setting115% × FLA = 39.1 A
Trip Class (IEC 60947-4-1)Class 10
Thermal Memory RecommendedNo — standard relay is adequate

Contactor

Required Equivalent Rating34.0 A
Recommended AC-3 Frame Size40 A

Ground-fault protection (guidance)

Pickup Setting6.8 A
Time Delay0.1s
Basis20% of FLA (min. 5A), fast definite-time — typical practice for solidly/low-resistance grounded systems