VFD Application Core Selection Guide

Common Mode Choke per Horsepower and Cable Length

MH&W Part # CBO43HP1/4-50A4 CBO43HP1/4-50A4 CBO68HP51-100A6 CBO155HP101-428A12 CBR166HP420-1631A16 CBO326HP1632+A23
Power Range (hp) *1/4-10 11-50 51-100 101-428 429-1631 1632+
Cable Length **
# Cores # Cores # Cores # Cores # Cores # Cores
150ft/50m 2 4 4 4 4 4
300ft/100m 4 4 4 4 4 4
450ft/150m 6 6 6 6 6 6
900ft/300m 8 8 8 8 8 8

Note 1 – Data above is for information/guideline purposes.
Note 2 – All cables/phases must travel through the Common Mode Chokes. Differential Mode Chokes are installed around each individual power cable, regardless of how many cables. Per application guide, Differential Mode Chokes are per cable. No ground or shielding through cores!
*Note 3 – On motors up to 10hp, two turns are needed through the Common Mode Chokes (pass cable through cores twice).
Note 4 – It is important to use the correct number and type of cores.
Note 5 – For servo and DC motors, please call Nanotech Engineering.
Note 6 – Install cores on load side of drive for typical motor applications. Cores may be installed on the line side of VFD as well to reduce conductive and radiated emissions back to the power grid.
Note 7 – MH&W offers brackets, and cable ties to hold cores in place. Please call Nanotech Engineering for alternative methods.

** Cable length between drive and motor must be multiplied by the number of cables per phase, to calculate the total cable length to be used in above guide for Common Mode Chokes. The actual length of each cable is used in the Differential Mode Chokes guide.
*** For cable runs over 950ft, contact Nanotech Engineering.
Contact your local Nanotech Engineer for detailed information.

Differential Mode Chokes per Horsepower and Cable Length

The use of Differential Mode Chokes increases the reliability of these systems by further reducing the noise and peak values.  These cores must be placed around each individual cable.

MH&W Part #  N18HP1/4-10 N18HP11-40 N29HP41-102 N57HP103-428 N75HP429-1631 N123HP1632+
Power Range (hp) 1/4-10 11-40 41-102 103-428 429-1631 1632 and above
Cable Length # Cores # Cores # Cores # Cores # Cores # Cores
150ft/50m 2 1 1 1 1 1
300ft/100m 3 2 2 2 2 2
450ft/150m 4 3 3 3 3 3
900ft/300m 5 4 4 4 4 4

It is important to use the correct number of cores to prevent the cores from getting too hot.

Note 1 – Data above is for information/guideline purposes.
Note 2 – All cables/phases must travel through the Common Mode Chokes. Differential Mode Chokes are installed around each individual power cable, regardless of how many cables. Per application guide, Differential Mode Chokes are per cable. No ground or shielding through cores!
*Note 3 – On motors up to 10hp, two turns are needed through the Common Mode Chokes (pass cable through cores twice).
Note 4 – It is important to use the correct number and type of cores.
Note 5 – For servo and DC motors, please call Nanotech Engineering.
Note 6 – Install cores on load side of drive for typical motor applications. Cores may be installed on the line side of VFD as well to reduce conductive and radiated emissions back to the power grid.
Note 7 – MH&W offers brackets, and cable ties to hold cores in place. Please call Nanotech Engineering for alternative methods.

** Cable length between drive and motor must be multiplied by the number of cables per phase, to calculate the total cable length to be used in above guide for Common Mode Chokes. The actual length of each cable is used in the Differential Mode Chokes guide.
*** For cable runs over 950ft, contact Nanotech Engineering.

Contact your local Nanotech Engineer for detailed information.