Motors and Equipment

Motor Calculations – Part IV: Branch-Circuit Short-Circuit & Ground-Fault Overcurrent Protection

Branch-Circuit Short-Circuit and Ground-Fault Overcurrent Protection is the final article of a four part series. The series is titled “Motor Calculations” and covers the Code and calculations for single general motor applications.

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Motor Calculations – Part III: The Motor Overload

This is the third part of a series designed to help explain how to properly calculate motor circuits.

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Motor Calculations – Part II: Motor Circuit Conductors

We considered how to properly size a typical motor branch circuit using the motor load as determined with the appropriate table and then multiplying that number by 1.25, reference 430.22.

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Variable Frequency Drives (VFD) Theory and Troubleshooting

By: David Herres – Variable Frequency Drives (VFD’s), also referred to as Adjustable Speed Drives, are prominent in today’s workplace. They are used in elevator, water pump, high-volume air compressor applications and material-handling systems wherever speed and torque characteristics of AC motors are regulated. In Thomas Edison’s time, the DC […]

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Motor Circuit Calculations – Part I: The Motor Load

We demonstrated how to determine the motor load for general motor applications using 430.6(A)(1) which states that table values shall be used to determine the ampacity of conductors… instead of the actual current rating marked on the motor nameplate.

Read Article

Recently in Motors and Equipment

Motor Calculations – Part IV: Branch-Circuit Short-Circuit & Ground-Fault Overcurrent Protection

Read Article

Motor Calculations – Part III: The Motor Overload

This is the third part of a series designed to help explain how to properly calculate motor circuits.

Read Article

Motor Calculations – Part II: Motor Circuit Conductors

We considered how to properly size a typical motor branch circuit using the motor load as determined with the appropriate table and then multiplying that number by 1.25, reference 430.22.

Read Article

Variable Frequency Drives (VFD) Theory and Troubleshooting

By: David Herres – Variable Frequency Drives (VFD’s), also referred to as Adjustable Speed Drives, are prominent in today’s workplace. They are used in elevator, water pump, high-volume air compressor applications and material-handling systems wherever speed and torque characteristics of AC motors are regulated. In Thomas Edison’s time, the DC […]

Read Article

Motor Circuit Calculations – Part I: The Motor Load

We demonstrated how to determine the motor load for general motor applications using 430.6(A)(1) which states that table values shall be used to determine the ampacity of conductors… instead of the actual current rating marked on the motor nameplate.

Read Article