Salary ceiling does not affect promotion.

Promotion is based on performance and the potential to take on responsibilities at the next level.

If you have hit the ceiling, you just stop getting increment for as long as you are in that sub grade.

Then again, at lower grades, or BT, officers are expected to have CEP of GEO 5 so long as you are not intending to hold appointments. ie just ordinary teachers. Your years in service, Sub grade, performance and some other factors will determine how fast you get to GEO5...

not too clear about the some other factors too...bottomline is, its not straightforward.