User blog comment:Nakama Power/Nakama Power's Equipment setup guide/@comment-75.97.16.91-20160118140204/@comment-25618730-20160202075748

It will only change it to a nightime CI set-up if you use a dual purpose AA gun like the 10/12.7cm HA since they also count as main/secondary weapons so you'd have 3. If you use a pure AA gun like the 25mm triple mount it won't as they count only as auxilary equipment. I've done it on my destroyers a few times for the evation bonus AA machineguns give back when I had no radars or anything else for them