in Latin, 'Pax' means 'Peace' and 'Primus' is 'First' not sure about the rest of it. the character spacing seems a bit odd as 'Rugellatty' and 'Paxandatch' mean nothing...
Someone has gone to an awful lot of trouble to prepare and put that there ! It may have some personal meaning - perhaps Rugaletty & Paxandatch are nicknames that only the installer and the people concerned will know .