I went and looked at a chiller plant in an uptown condo in the high rent district of Miami Beach on Friday. My company wanted it evaluated to see if we wanted to take it under contract. The plant contains a three year old R-123 YTG and a 1991 R-11 YTD that share one chilled water pump, one condenser pump, one cooling tower and one breaker! The building has gone through at least 4 property management companies in as many years, with the present company only there a month. The YTG was running and no one knows when the last time the older machine ran. They wanted it checked out to see if it could run to be used as a backup. Other than being full of air with a nasty leak at the rupture disk flange, which was so corroded it looked like it was ready to snap off, it was actually in fairly good shape. I'm going to go back next week some time and repair the leak and see if I can fire it up, but only after they have an electrician come out and give them an estimate to put it on it's own breaker. Then we're going to sell them a repiping job and two new pumps to get some true redundancy out of the system.
It just blows my mind that it was ever set up like that and passed inspections. The only thing I've ever seen that was close is a chiller plant at a hospital with two chillers and one power supply. But there they used an emergengy power style transfer switch with an interlock to make sure only one chiller could run at a time. Anyone ever seen anything like this before?