to take 5-4-4-4-4 hours for each day i use :
min 4 hours for teacher AND
max 5 hours for teacher
is this the best move?
It is a good move, but I think not the best. See below:
You could try a comparison:
1) Min 4 hours, max 5 hours
2) Min 4 hours, min 5 days per week
3) Min 4 hours, max 5 hours, min 5 days per week (all 3 constraints).
But you need to generate more timetables to see which is better.
I would prefer the other approaches than yours: (2) and (3), because it tells FET that the teacher must work 5 days and helps the algorithm.