A drop of oil was hanging from the tee, which means there’s a leak there.
The installation is called the “Salad Bar.” It’s located in a restaurant of a popular chain. Essentially, it’s an octagonal structure made of laminated particle board with openings on top for salad pans, below which are two evaporators with fans, and hidden behind decorative panels in the countertop is the refrigeration unit. The little T-joint that is planned to be replaced connects the “warm” pipes coming from the evaporators to the pipe leading to the compressor. It’s poorly designed from an engineering perspective, but the design is such that the cooling mechanism is not noticeable. Accessing any point inside is difficult and requires acrobatic skills. The doors at the bottom are small, but thankfully there are two of them.
We’re removing the T-joint. To take it off, we unsolder the tube from one of the evaporators and push it down. We plan to assemble the T-joint outside of the installation and then insert it back in, slightly repositioned. Originally, it was located under the ceiling of the lower compartment of the octagonal box, and we didn’t want to solder there with an open flame near the plywood. By the way, someone has already soldered there — the plywood is charred.
We removed the tee fitting. The pipe leading from the other evaporator is thick. Aha, a leak, so it’s not at the tee fitting. We check how crooked all the pipes are – they’re bent with kinks, misaligned, and welded together from several pieces – we decide to remove the pipe from the second evaporator and replace it — it’s oily and looks bad. Because if this nonsense breaks again, we really don’t want to deal with it. When we took off the second pipe, it turned out that someone had poorly soldered it to the evaporator not with an overlap, but end-to-end. And, of course, that’s where the leak was. Idiots.
We rebuilt everything from fresh, beautiful pipes that were nicely cut, properly bent, and deburred. We insulated it with Armaflex. We pressure tested it, vacuumed it, and charged it with refrigerant. It looked great. We turned it on – and it didn’t work. Damn. The compressor is dead. Well, first there was a leak, which we ignored, even though the unit seemed to have stopped cooling, and then the compressor just quietly gave up. We’re pumping the refrigerant back out. I’m removing the old compressor – cutting the pipe, unscrewing the electrical connections, loosening a couple of nuts, and taking off the cabinet door to pull out the compressor since the door doesn’t open wide enough for it to come out. Meanwhile, my partner is rushing off like a wild boar to get a new one – luckily, there’s a wholesale compressor seller nearby.
We’re installing a new compressor. We vacuum it. We charge it with refrigerant. We turn it on… and it runs poorly. We think the valves on the evaporators are shot… both of them… no, that’s unlikely. It turned out we hadn’t closed the valve that connected the manifold (and the refrigerant tank) to the cooling circuit. Phew. Everything works now. It cools down and doesn’t even make noise. We’re great. But we spent from 8 AM to 6 PM on this. It seemed like it was just a matter of replacing a tee fitting…