Case of the Freezing Compressor Wires

It was a warm August day when my Baskin-Robbins ice cream franchise received an order for a wedding cake that would serve 200 people. Putting together such a large cake was a task that required assembly in the walk-in freezer.

The freezer was an 8-foot by 10-foot room with a freezer powered by a 220V three-phase compressor unit. We kept the temperature at -5 degrees F. I was putting together the cake three days after an ice cream delivery, so the freezer was quite full, which didn't leave me much room to work.

I made a table out of stacked-up three-gallon ice cream tubs. At this super-low temperature with the blower blasting, I couldn't stay inside more than seven or eight minutes, even with my heavy winter coat on.

When I'd open the freezer to go in or out, the temperature on the thermometer would rise eight to 10 degrees, and it would take a few minutes to recover. As I worked on the cake, I noticed that the temperature was not recovering. It had risen to about 20 degrees F. The blower fan was working OK, but the compressor on top of the freezer didn't sound right.

I checked the fuses and found that one of them had blown. I replaced it, but it blew again right away. There are two boxes on each side of the blower unit inside of the freezer. The one by the door had the low-voltage circuitry. Everything looked OK there. The one in the back enclosed the power-in connections.

I opened that one up and found that one of the connections on the terminal strip had broken away from the strip. The two wires that were screwed together had fallen away from the strip and shorted out against the box cover. There was a black mark from the short. I used some electrical tape to tie up the wires and solve the problem. I powered it up with a new fuse and the compressor sounded like its old self. I was able to finish the cake on time.

This entry was submitted by Jim Owen and edited by Rob Spiegel.

Jim Owen has a machinist background and moved on to become a customer service engineer for Teletypesetter Corp., installing and servicing automated printing equipment. He then worked as a head linotype machinist, a model-maker for Schwinn Bicycle Co., and as a supervisor in an medical x-ray equipment manufacturer. Finally, he became the QA manager for an x-ray machine component manufacturer. He owned an ice cream shop along the way.

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