Server room aircon - how not to wire it!
Was showing a contractor where some cabling needed to be finished in our new server room earlier - its got the 'old' and the £22k worth of 'new' servers in there.
Open the door to be blasted by the heat. Air con has no life, its only 3 months old. Phone up electrician who sorted it out - he comes out - and after much head scratching realised he had cabled it into the emergency stop button in the dt room next door.
Which the dt teacher does randomly through the day and every night and weekend.
Great start to the day!