When we have a normal motor with a pulley or that is going to start working with pulleys, If it doesn’t have a roller NU bearing, normally we replace the 6xxx ball Bearing for one NU xxx roller bearing (because of the radial forces created by the belts in the pulley). In case of an ATEX motor (for example Ex d IIB or IIC), can we also make the change and maintain the ATEX classification? Thank you