How to Select the Correct CoolBLUE Inductive Absorber Cores for your Application

Posted by Lynn Dreisilker on Nov 15th 2022

How to select the correct CoolBLUE Inductive Absorber Cores for your application

A guide to picking the correct CoolBLUEs for your VFD application.

What are CoolBLUE Inductive Absorbers?

CoolBLUE Inductive Absorbers act as a common mode choke in order to protect motor bearings from high frequency emitted by variable frequency drives.

What information do you need in order to seleect the correct CoolBLUE rings for your application?

The most important information you need for selecting CoolBlue Inductive Absorber rings is the HP rating of our electric motor and the length of the lead wires.

What types of products do you need for selecting CoolBlue?

When selecting CoolBlue Inductive Absorber rings, it’s important to know that you need more than just one ring and you need two different types of CoolBlue products – the CoolBlue Cores and the NaLA cores. We will walk you through how to select these products below.

How to select the correct CoolBlue for your application:

As mentioned above, you need to select CoolBLUE cores for your application based on the HP rating of your electric motor, as well as the length of your lead wire. We have provided a chart for you to understand which CoolBLUE core you need, as well as how many of them. Simply find the range of your HP and match it with the length of your lead wires.

CoolBLUE HP # of Cores
Part Number Range 1-150 ft 151-300 ft  301-450 ft  451-900 ft 
1/4-10 2 4 6 8
CBO43HP1/4-50A4 11-50 4 4 6 8
CBO68HP51-100A6  51-100 4 4 6 8
CBO155HP101-428A12  101-428 4 4 6 8
CBR166HP429-1631A16      429-1631 4 4 6 8
CBO326HP1632+A23 1632+ 4 4 6 8

For example, if you have a 10 HP motor and the lead wires are under 150 feet long, you will need quantity 2 of the CBO43HP1/4-50A4.

Once you have selected your CoolBLUE cores, now it’s time to select the NaLA cores for your application.

How to select the correct NaLa coolblue for your application:

Selecting the correct NaLA cores is similar to selecting the CoolBLUE cores, however, you will need to take into account how many lead wires you have.

NaLA Core HP # of Cores  per cable
Part Number Range 1-150 ft  151-300 ft  301-450 ft  451-900 ft 
1/4-10 2 3 4 5
N18HP11-40 11-40 1 2 3 4
N29HP41-102 41-102 1 2 3 4
N57HP103-428 103-428 1 2 3 4
N75HP429-1631        429-1631 1 2 3 4
N123HP1632+ 1632+ 1 2 3 4

Again, we’ll look at the chart to see where your HP rating falls and match it up with the length of the lead wire. In our previous example, we have a 10 HP motor that’s lead wires are under 150 feet long. When looking at the chart, you will see that it says “2” for the part number N18HP1/4-10. This does NOT mean that you need only 2 of these NaLA Cores. This means that you need 2 NaLA Cores PER lead wire – 6 NaLA cores (2 cores multiplied by 3 lead wires).

In this example of selecting your CoolBLUE inductive absorbers, you need quantity 2 CBO43HP1/4-50A4 CoolBLUE Inductive Absorbers and 6 N18HP1/4-10 NaLA cores.

Special things to consider when selecting your coolblue

Whenever you have a motor that is 10 HP and lower, you need to pass the lead wires through the CoolBLUE cores two times (wrap them around the core). This is only needed on the CoolBLUE cores and not the NaLA cores and this is only for 10 HP and below.

If you have a motor with Aegis Grounding rings installed, you can still install CoolBLUE on your motor application with the grounding ring. The benefit of the CoolBLUE cores is that you do not need to maintain the cores and they will last the lifetime of the motor.

If you have a motor that has lead wires over 900 feet, please consult with Dreisilker Motor Experts to find the correct CoolBLUE solution for your setup.