After issuing "/OS SET LOGCHAN ON" there will be no bot in the log channel unless it is a registered channel with a bot assigned to it but messages will still be sent there by the Global Noticer if there is someone in there.
Eg.:
<G> O: NickName: set logchan on
<G> Now sending log messages to #channelname
I suggest registering the channel and securing it so other users cannot enter it.
Eg.
/msg ChanServ SET #channelname SECURED ON
/msg ChanServ SET #channelname MLOCK +i
Just as an example.
[Edited on 18-5-2006 by Jobe1986]