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HVAC Electrical Sizing Calculator

Motor-compressor branch-circuit sizing (NEC Article 440) or general method (IEC 60364-5-52). Single motor free — multi-motor combination-load equipment and VFD-fed motors are subscriber features.

AAJappsEngineering Calculation Report

HVAC Electrical Sizing Calculator

NEC Article 440, IEC 60364-5-52

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.

Standard basis

Single motor-compressor

A
A

Multi-motor combination-load equipment

Subscriber

VFD-fed motor

Subscriber
A
A

Single motor-compressor result

Minimum Circuit Ampacity (MCA)22.5 A
Max Overcurrent Protection (MOCP)35 A (standard size)
Disconnect Min. Ampacity20.7 A minimum
IEC Design Current—

Combination-load result

Largest MotorCompressor (18 A)
Combination MCA26.5 A
Combination MOCP39 A

VFD-fed motor result

Input-Side MCA31.3 A
Output-Side MCA27.5 A