AC Mobile, Shore Power & Motor Surge Calculators
Engineering tools for mobile AC electrical systems: shore power cord drops, inverter transfer relay coordination, induction compressor starting inrush (LRA), and marine cathodic protection.
Shore Power
Shore Power Cable & Voltage Drop Sizer
Calculate delivered voltage and cord heat loss across 25ft to 100ft extension runs for 30A (120V) and 50A (120/240V) pedestals.
Interior Wiring
AC Branch Circuit Conductor Sizer
Sizes 120V and 240V interior branch wiring under ABYC E-11 stranded boat cable and NEC 310.16 multi-conductor cable thermal limits.
Inverter ATS
Inverter/Charger Passthrough & Shore Coordinator
Coordinates shore power current limits with inverter transfer switches, dynamic battery charging throttles, and hybrid PowerAssist boosting.
Generators
Generator Sizing for Motor Surge & LRA
Evaluates inductive compressor locked rotor amps (LRA) vs generator peak surge capability, accounting for combustion engine elevation derating.
Soft Starters
Soft Starter Inrush & Inverter Sizer
Calculates inrush reduction for rooftop A/C compressors and verifies if a 2000W–3000W lithium inverter system can successfully start the unit.
Cathodic Safety
Marine Galvanic Isolator Selector
Sizes ABYC A-28 fail-safe galvanic isolators to block destructive marina DC stray currents while maintaining full AC safety ground continuity.
Mobile AC Engineering Principles
Alternating Current (AC) in mobile environments presents fundamentally different physics and hazards than terrestrial residential wiring:
- Vibration and Conductor Fatigue: Solid copper conductors used in house wiring crack and break under continuous vehicle or wave motion. Mobile AC systems require high-strand flexible copper conductors (ABYC Type III).
- Inductive Reactance: AC voltage drop must account for 60 Hz inductive reactance ($X_L$) alongside resistance ($R$), particularly on heavy extension cord runs and tightly bundled sheathed cables.
- Electric Shock Drowning (ESD): On marine shore connections, faulty AC grounding creates deadly leakage currents in freshwater docks. Strict galvanic isolation and ground-fault protection (ELCI) are critical life-safety requirements.