You can retire from your preservation fund any time after the age of 55. There might be certain tax implications when you do retire from your preservation fund that you would need to consider.
A preservation pension fund allows you to access up to 1/3rd of the funds in cash, subject to taxation, while the remaining 2/3rds must be used to purchase an income for life (Living annuity or guaranteed annuity) at retirement. If your fund value is less than R 247 500 when you retire you can access the full amount in cash, subject to taxation.
A preservation provident fund allows you to access up to the entire fund value in cash at retirement, subject to tax. The portion not withdrawn must be used to purchase an annuity product.