The mounting positions of electric motors are summarized in the table below.
Remarks: the specified mounting must always be mentioned when ordering an electric motor. The actual motor mounting may influence the protection class and bearing design. Flange mounted electric motors need further specification of the required pitch circle diameter (dimension M) of the fixing holes in the flange (FF or FT type of flange). FF (Flange Free Holes) = free holes are in B5 flanges, FT (Flange Tapped Holes) = tapped holes are in B14 flanges. The pitch circle diameter (dimension M) is specified in the EN50347 standard in relation to the frame size for the FF (B5) flange and the FT (B14A) flange (up to 160 frame). The pitch circle diameter (dimension M) is not specified for FT (B14B) flanges in the EN 50347 standard, they however are specified in IEC 72-1 standard. The motor mountings and the positions are summarized in the IM code as per the table below. For detailed information please consult the IEC 34-7 (NEN 10034-7) standard.