WireGaugeCalc Free calculator · NEC cited · works offline
100 Hp Motor Fla
100 hp motor fla is fast with WireGaugeCalc, since you pick the horsepower and voltage and the app returns the NEC table value.
It reads the full-load current from the motor tables instead of the nameplate, as the NEC requires table values for conductor and overcurrent sizing.
You get a clear FLA figure in seconds so you can move on to wire and protection sizing.
Open the calculatorEnter any two values and read the rest.
Ohm’s law: V = I × R and P = V × I. Field aid only, verify against the current NEC and your local authority having jurisdiction.
Why 480v Motor Fla Comes From The Tables
The NEC uses full-load current from Table 430.250 for conductor sizing, so a 480v motor fla value is read from that table, not the nameplate.
A 100 hp three-phase motor at 460V draws about 124 amps from the table, since horsepower and voltage set the value.
Using the table number keeps your conductor and overload sizing consistent with code.
What Drives The Full-Load Current
A few inputs set the full-load current for a large motor:
- Horsepower rating, here 100 hp
- Supply voltage, such as 460V or 230V three-phase
- Phase count, single or three phase
- NEC table values for sizing, nameplate for overload setting
- Conductor at 125% of FLA for a single continuous motor
One app for every NEC calculation
WireGaugeCalc keeps the calculations you reach for most in one place:
- Voltage drop and wire sizing for any run
- Conduit fill for EMT, PVC, and RMC
- Box fill and junction box sizing
- Ampacity and temperature derating
- Motor circuit and load calculations
- Conduit bend offsets and saddles
Built for the field, works offline
The whole app runs on your phone, so it keeps working in a basement, an attic, or a job site with no signal.
There is no account to create and nothing to load. Open it, run the number, and get back to work.
- No signup and no signal needed
- Answers in a tap, not a spreadsheet
- Same tool on phone, tablet, and desktop
Every result cites the NEC article
Each answer shows the table or formula it came from, so you can check the method and learn the code as you go.
That makes the app useful on the job and during exam prep, since the reasoning is right next to the number.
Switch the code year your job runs on
Jurisdictions adopt the NEC at different times, so you can match the calculation to the code in force:
- NEC 2017, 2020, and 2023 tables
- Copper and aluminum conductors
- 60, 75, and 90 degree C terminations
- Single-phase and three-phase systems
Run the number, then get back to work
Stop flipping through a paper book or hopping between calculator sites. Enter your values, read the code-cited answer, and move on. Free to use, no signup.
Open the calculatorFrequently asked questions
Do I use the nameplate amps or the table FLA for a 100 hp motor?
Use the NEC table full-load current to size conductors and feeders. The nameplate current is used to set the overload protection. Always confirm against the current NEC and your local authority having jurisdiction.
What size conductor does 100 hp at 460V need?
The table FLA is about 124 amps, so conductors are sized at 125% for a single continuous-duty motor, roughly 155 amps. Pick the wire from the ampacity table for your termination temperature.
Is WireGaugeCalc free to use?
Yes. Every calculator is free to run with no signup. A paid tier adds saved projects, PDF reports, and extra code years, but the core math stays free.
Does it work without internet?
Yes. The app runs on your device, so it keeps working with no signal on a job site, in a basement, or in an attic.
Are the results code accurate?
Results follow published NEC tables and standard formulas, and each answer shows the article it came from. It is a field aid, not a stamp of approval, so verify against the current code and your local authority before you wire anything.
Which NEC code year does it use?
You can switch between NEC 2017, 2020, and 2023, since jurisdictions adopt the code at different times. Pick the year your job runs on.