Examples/Motor Starter Sizing

Motor Starter Sizing Tool

Stop cross-checking motor tables and resizing starter components every time the motor changes.

Change motor horsepower or voltage and the breaker, contactor, overload, and reported outputs update together automatically. LogiDraft uses coordinated lookup-driven logic so the starter and data stay aligned.

Change motor HP and watch breaker, contactor, and overload update together instantly.

Open in workspace

InputsMotor HP, line voltage, coil voltage

Lookup OutputFLC, contactor, breaker, overload

Voltage Options240 or 480 V line, 24 or 120 V coil

Motor Range1 to 30 HP

Automatic motor starter sizing and coordination

This starter is generated directly from the same logic used in the workspace.

At 1 HP @ 240 V: 4.2 A FLC, 15 A breaker, 10 A contactor, 5-10 A overload.
At 30 HP @ 480 V: 40 A FLC, 100 A breaker, 60 A contactor, 20-40 A overload.

Change horsepower or voltage and the starter updates automatically.

Motor Starter Sizing example showing a 1 HP 240 V starter with coordinated breaker, contactor, overload, and motor data — 1 HP @ 240 V

Motor Starter Sizing example showing a 30 HP 480 V starter with coordinated breaker, contactor, overload, and motor data — 30 HP @ 480 V

Increasing motor size updates breaker, contactor, overload, and motor data together.

Change inputs in the workspace and this result updates automatically.

These changes are reflected directly in structured output data.

Motor	FLC (A)	Breaker (A)	Contactor (A)	Overload Range (A)
1 HP @ 240 V	4.2	15	10	5-10
30 HP @ 480 V	40	100	60	20-40

Geometry and data stay aligned because they are generated from the same logic.

Inputs and outputs

Motor requirements resolve the coordinated starter components and the reported outputs together.

Inputs

Motor HP
Line voltage
Coil voltage

Outputs

FLC
Contactor rating
Breaker size
Overload range
Schematic

Lookup-driven starter design logic

A lookup table maps motor horsepower and voltage to the required electrical components.

Resolved logic

Motor data comes from a lookup table with FLC based on HP and voltage.
Contactor current is selected from the same lookup data.
Breaker size is selected from the coordinated table output.
Overload trip range is selected automatically.
Coil voltage propagates into the contactor portion of the starter design.

Why that matters

This keeps breaker, contactor, overload, and motor aligned as one system. Changing motor requirements updates the entire starter automatically.

Coordinated selections are reflected directly in the resolved starter outputs.

Motor	FLC	Breaker	Contactor	Overload
1 HP @ 240 V	4.2 A	15 A	10 A	5-10 A
5 HP @ 240 V	15.2 A	40 A	20 A	10-20 A
15 HP @ 480 V	21.0 A	60 A	40 A	20-40 A
30 HP @ 480 V	40.0 A	100 A	60 A	20-40 A

Outputs

The resolved starter produces usable engineering data that can be exported and kept aligned with the schematic.

Motor, breaker, contactor, and overload values are available as generated data from the same evaluated starter.

Exported data stays aligned with the visible result, which keeps reporting and downstream review in sync with the design.

Generated data can be exported as CSV or JSON.

Component	Role	Resolved output
Motor	Load	5 HP, 240 V, 15.2 A
Contactor	Control	20 A contactor, 24 V coil
Circuit Breaker	Protection	40 A, 3-pole, 240 V
Overload	Protection	10-20 A range, class 10