Scaling in on MT5

Hi there!

I have a question about scaling in on MT5 and i really hope one of you can help me out.
I want to add to my position once it hits 50% of the trade. The moment I scale in to a position a new entry is calculated and to keep my risk the way it was i want to place my SL under this new entry.
The question is, once it hits this SL will it close the total position or just the position i have added the last?