We have been asked to look at a Kaukan oil cooler, model KO-6PTS which is being used on a Doosan milling machine. Unit is intermitantly tripping on alarm EO4 which is high pressure alarm (refrigerant side). There is no obvious reason for this. We were the site and the cooler was working well, however it had alarmed twice within an hour earlier in the day.

Suspect it could be a faulty pressure switch. Anyone else had any issues with these?