Category
Motors & Loads calculators
Motor load, starting, protection, and cable-screening calculators for rotating equipment review.
- Calculators in category
- 16
- Related categories
- 6
Electrical Load Calculator
Estimate demand load, service current, and a recommended U.S. service size for dwellings and preliminary non-dwelling projects.
Motor Current Calculator
Compare NEC table full-load current with formula current, screen starting current, and check preliminary AC motor branch-circuit sizing.
Full Load Current Calculator
NEC Table 430.248/430.250 motor full load current (FLC) lookup with conductor sizing, overload-basis reminder, and branch-circuit breaker requirements
Motor Power Calculator
Calculate motor electrical and mechanical power, efficiency, and perform power unit conversions
Motor Efficiency Calculator
Screen one motor operating point from shaft output and either measured input power, one efficiency value, or a simple two-efficiency comparison.
Motor Starter Calculator
Screen NEMA starter size, controller current class, overload-relay setting range, and basic control-package notes for common U.S. motor starters.
Motor Starting Current Calculator
Screen induction-motor starting current and compare DOL, star-delta, soft starter, VFD, and autotransformer starts.
Motor Branch Circuit Protection Calculator
Screen NEC Article 430 motor branch-circuit short-circuit and ground-fault protective device sizing from motor FLC, motor type, and device type.
Motor Torque Calculator
Calculate motor torque, speed, and power relationships for motor selection and mechanical design
Motor Protection Calculator
Size motor protection devices including overload relays, circuit breakers, and fuses per NEC requirements
Motor Cable Sizing Calculator
Screen AC motor branch-circuit conductor size with NEC table FLC, ampacity adjustments, termination limits, and branch-circuit voltage drop.
Motor Control Panel Load Calculator
MCC feeder ampacity screen from the largest motor FLC, remaining motor FLC, non-motor kVA, and planning spare capacity.
Single Phase Motor Calculator
Calculate single phase motor current, power, efficiency, and starting characteristics
Three Phase Motor Calculator
Balanced three-phase motor operating-point screen for line current, input power, apparent power, reactive power, and estimated shaft output.
NEMA Starter Sizing Calculator
Select NEMA motor starter size based on motor HP and voltage per NEMA ICS 2
Soft Starter / Motor Starting Calculator
Estimate motor starting current and compare common starting methods using horsepower, voltage, and a NEMA locked-rotor code basis.
Motors & Loads Overview
The motor category covers preliminary checks for rotating equipment, including current, starting behavior, conductor and protection assumptions, starter selection, and load effects. These calculators support early screening before the work moves into motor documentation, controller data, and project-specific design review.
Application guidance
Review the operating assumptions, installation conditions, and code checkpoints that most often affect results in this category.
Load, starting, and protection scope
Motor work becomes confusing when several questions are mixed together. A load review, a starting-current estimate, and a branch-protection screen each need different inputs and a different expectation for the output.
- Load and current tools fit operating-point review.
- Starting and starter tools fit questions driven by inrush, controller choice, or line effect.
- Protection and cable tools become more relevant when the output must support conductor or OCPD screening.
Table FLC and nameplate-data basis
Motor calculations often depend on whether you are using NEC table full-load current, measured operating current, or a manufacturer nameplate current. Those numbers serve different purposes and should not be swapped casually.
- NEC table values belong to workflows where the code path calls for them explicitly.
- Actual nameplate or measured values are more appropriate for operating review and equipment comparison.
- The basis used should remain explicit before the result moves into sizing or troubleshooting.
Motor documents and final review
A motor calculator works best as a fast screen before the motor data sheet, controller documentation, and project sequence of operation drive final settings and equipment selection.
- Duty cycle, service factor, enclosure type, and ambient assumptions still need confirmation on the real equipment.
- Starter, overload, VFD, and feeder details belong in the actual one-line and control documents.
- The category output is most useful for narrowing decisions before final review, not replacing it.