Now I've never used a RL02 drive on 50Hz power,
but I'm 99% certain that
the motor speed in a RL02 is determined by a servo loop, and thus
not locked to a multiple of the AC frequency.
I think the fan in a 50Hz RL02 will run a bit slower, but I don't think
this will hurt anything.
Motor speed is controled by line mains freq. I think the 50hz unit has
a differnt spindle size. I havent looked under one in 15 years.
Allison