HVAC MCA & Electrical Load

HVAC Electrical Load & MCA Calculator is the professional tool for HVAC technicians and electricians. Calculate Minimum Circuit Ampacity (MCA) and Maximum Overcurrent Protection (MOCP) sizing per National Electrical Code (NEC) Article 440 requirements for air conditioning equipment installations.

EQUIPMENT TYPES SUPPORTED:

Split AC Systems — Standard residential split-system air conditioners

Package Units — Rooftop and packaged equipment configurations

Heat Pumps — Electric heat pump systems with auxiliary heating

Mini Split Systems — Ductless mini-split and VRF installations

PTAC Units — Packaged terminal AC for apartments and hotels

VOLTAGE OPTIONS:

Single-Phase: 115V, 208V, 230V (residential and light commercial)

Three-Phase: 208V, 230V, 460V (commercial and industrial)

ELECTRICAL CALCULATIONS (NEC 440):

MCA Sizing — NEC 440.32: 125% of largest motor plus all others

MOCP Selection — NEC 440.22: Maximum overcurrent protection sizing

Wire Size Recommendation — AWG per NEC Table 310.16 ampacity

Breaker Selection — Standard breaker size selection for protection

INPUT PARAMETERS:

Compressor RLA (Rated Load Amps) rating

LRA (Locked Rotor Amps) startup current

Fan FLA (Full Load Amps)

Auxiliary heater load current

Multiple equipment combinations

FEATURES:

100% Offline — No internet connection required for calculations

Works in field without cellular coverage

English & Spanish language support

Dark theme for outdoor visibility

PROFESSIONAL TOOLS:

Save calculation history for job reference

Export results to PDF for electrical documentation

No ads — focused professional experience

Ad-free dark theme for extended use

WHY ELECTRICIANS & HVAC TECHS USE THIS APP:

Faster electrical load calculations than manual NEC charts

Ensures code-compliant wire and breaker sizing

Prevents undersized circuits that risk failure

Prevents oversized protection that ignores equipment

Cross-check MCA and MOCP calculations

Reduces electrician callbacks and callbacks

PERFECT FOR:

HVAC technicians estimating electrical requirements

Electricians sizing circuits for AC equipment

AC contractors preparing accurate project bids

Electricians qualifying under NEC Article 440

HVAC apprentices learning code requirements

Building maintenance engineers planning upgrades

NEC Article 440 compliant calculations for safe, code-approved AC installations.

Part of HVACTools Suite — professional HVAC technician and AC service tools for field calculations and system diagnostics.