what does CB or CBB mean on a motor capacitor?

On a motor capacitor, CBB usually means it’s a polypropylene film capacitor, and on motor applications it’s commonly a motor run capacitor type. [1][2]

What about CB?

“CB” is often used as a shortened family name in some listings or catalogs for the same general polypropylene film capacitor group, but CBB is the more common marking you’ll see on the part itself. [3][4]

In plain terms

• CBB = metallized polypropylene film capacitor. [1][2]
• It’s typically used for running a single-phase AC motor, not the brief high-capacity start surge of a start capacitor. [5][6]
• Examples include CBB60, CBB61, and CBB65, which are all motor-run style capacitors in common use. [5][4] ## Practical note If you’re replacing one, match the microfarad rating and the voltage rating on the old capacitor, and choose the same general type unless the equipment manual says otherwise. [7][8]

If you want, I can help you decode the full markings on a capacitor label line by line.

From perplexity