Asynchronous motors have a slip that causes them to go at a slower speed than those of synchronism, in this case 3000 RPM.The manufacturer ensures that it does not turn below that speed that depends on friction, temperature, amount of air, etc.In addition, the speed depends on the frequency, which can be more than 50Hz. It is different if you use the network frequency, which is stable.You should worry if it spins at a slower speed than the one mentioned by the manufacturer and not faster.