Motor Voltage

Choose the closest input voltage to what is listed on the motor nameplate or manufacturer's specification.

Horsepower

Choose the horsepower that matches or exceeds what is listed on the motor nameplate or manufacturer's specification.

Temperature Limit

Select this limit based on the lowest rated component in the motor cable drive system (typically the drive). Always confirm manufacturers' temperature ratings before selecting a cable. Lower temperature limits require larger gauge cables to reduce cable heating of the system.

Ambient Temperature

Select the environmental temperature surrounding the cable installation. Higher ambient temperatures reduce cable ampacity, resulting in the need for a larger gauge cable.

Upsizing

Consider upsizing your cable solution for the following reasons:

1. Reducing voltage drop to acceptable manufacturers' recommendations (due to long runs), or
2. Better performance for constant or cyclic heavy loads that may exceed the motor nameplate rating, or
3. When using an upsized drive (relative to your motor's needs) for any reason

Multi-Cable Option

The use of parallel conductors may create more economical solutions that are easier to install and terminate for large motors of 200 HP or more (minimum cable size of 1/0 AWG).

Cable Length

Longer runs may require upsizing cables to reduce voltage drop because voltage drop is directly proportional to cable length. See the technical information section of this page for maximum recommended run length and always consult manufacturers' recommendations for allowable voltage drop.

Gauge

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Full-Load Current (FLC)

Based on NEC table 430.250 for selected motor horsepower and voltage ratings.

Base Conductor Ampacity

Based on NEC guidelines.

Voltage Drop

The loss of voltage due to cable resistance. If this parameter exceeds manufacturers' recommended limits, consider upsizing your cable solution or reducing your run length (if possible). Many drive manufacturers recommend voltage drop be limited to 2 or 3%.

Disclaimer

The cable recommendation shown is estimated using a general set of parameters and may not be applicable to any given situation. Always consult your Local Authority having Jurisdiction for local and regional code compliance and interpretation questions.