Hello,
There was a translation in french which doesn't make sense for me, os I go see the original :

xfce/power-manager/po/fr.po

116#: ../data/interfaces/xfpm-settings.ui.h:22
117msgid "Spin down hard disks"
118msgstr "Test des disques durs"


The 118msgstr translated back would be "Check hard drive" which is not what we want:
Something like:
"Mettre les disques durs au repos"
may be better.

I think it's worth filling a bug because the translation is not a all in relation with the action.

Ciao.