WireGaugeCalc Free calculator · NEC cited · works offline
5hp Motor 480v To Amp
5hp motor 480v to amp is quick with WireGaugeCalc, which reads the full load current straight from NEC Table 430.250.
It converts horsepower to FLA amps for three-phase motors so you size the conductors and overload from a code value.
You see the amps in one tap and move on to picking wire and protection.
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.
Horsepower To FLA Amps At A Glance
A 5 horsepower three-phase motor at 480 volts draws about 7.6 amps full load per NEC Table 430.250.
The app uses the table value rather than a formula, since the code requires table FLA for conductor and protection sizing.
Changing the voltage or horsepower updates the amps instantly, so you can compare 460V and 480V wiring quickly.
Sizing The Circuit From The FLA Amps
Once you have the full load current, the app carries it through the rest of the motor circuit:
- Full load amps near 7.6 A for 5 HP at 480V three-phase
- Branch conductors at 125% of FLA per NEC 430.22
- Overload set between 115% and 125% of FLA
- Breaker or fuse ceiling from NEC Table 430.52
- Copper conductors rated at the 75C column
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
Why not just use the formula HP times 746 divided by volts?
The formula ignores efficiency and power factor, so it underestimates current. For conductor and overload sizing the NEC requires the full load amps from Table 430.250. Always check the current table values and your local authority having jurisdiction.
Is the FLA the same for 460V and 480V motors?
NEC Table 430.250 lists motor values at 460 volts, and you use that same FLA for a nominal 480 volt system. The slight nameplate difference does not change the table value you use for sizing.
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.