The temporary directories (
%TMP%\) are growing up too fast on IIS service node.
Plesk Automation does not remove files from temp directories automatically on Windows Service Nodes. The behavior was caused by software issues #PPA-2302 and #PPA-2304. The fix is included in PA 11.5 MU#11.
In order to fix the issue please install update 11 as described in the article.