In india we can't get power frequency less than 48.5hz.
Below this frequency power system violate.
If we run motor below this range than motor coil will be 
burn due to more losses.

Actually in india our all power system equipments are 
designed to operate at 50 HZ. at lower frequency 
performance of these component is poor in view of power, 
life of equipment and safety. Motors will run slower, 
transformers output will reduce, harmonics will increase in 
power system. second thing when you run generator at 
47.6HZ, your generator will loss its synchronism with the 
grid.

since all the equipments are designed to run at a frequency 
of 50 Hz ( +/- 2 Hz) , low freuency will make the generator 
to run at a speed less than the designed value thus 
hindering the designed value of output.

Generator will go out from synchronizm with grid.