Motor Insulation Class

[bryan8392]

Hello,

I am by no means an expert with electric motors, so I have a question about insulation class. I have seen motors with insulation class B5 and F4 on the nameplate, and I was wondering what the 5 and 4 mean. I can't seem to find an answer anywhere so maybe this is something that is specific to a manufacturer, but I am not sure. Any help would be appreciated!

Thanks!

 

[electricpete]

Never heard if it. My vote is that it is manufacturer-specific.

=====================================
(2B)+(2B)' ?

 

[hooverdale]

Insulation classes are classified only as A,B,F and H.
If i am not mistaken. B5 would be a motor mounting type.
As B5 is flange mounted and B3 is a foot mounted

I'm not familiar with F4 though. This should somehow refers to the number of pole. As motor models usually have this.

But if you are sure that this was printed as insulation class on the nameplate. Then i am with pete, its a manufacturer's specific.

 

[Brad1979]

Just to be clear on terminology, according to UL 1446, an insulation system is a unique combination of insulating materials used in electrical equipment. An temperature class of an insulation system tells the maximum hot-spot operating temperature. The class is designated by a single letter, often A, B, F, or H. The system can be designated by other names. What you are probably seeing is the name of the insulation system and, as others have said, this name is probably company specific.

 

[bryan8392]

The nameplate INS: F4 so it is probably just something for the manufacturer. Thanks for the help!