Combination start "relay" overload

mattmia2

So about a year and a half ago my mom's refrigerator was having some intermittent issue starting the compressor, it appears it finally burned out the overload after decades of short cycling. It is a Frigidaire from the 80's and there is a hole in the back of the cover over the controls in the refrigerator compartment that directs the cold air from the evaporator on to the cold control and causes it to short cycle. Anyhow since It wasn't entirely clear if the issue was the start relay or overload I replaced both with a Supco combination overload/relay. After working ok but running kinda long cycles after plugging the hole in the control housing, it stopped working about a week ago. Since it appeared to have cabinet issues that were causing either water logged insulation or air leakage but it seemed to run almost constantly so it was replaced so this is just for information.

I did an autopsy on the failed overload/"relay" combination.




The silver disc is a thermistor that is the "relay"
I unsoldered the red wire and tab ro remove the overload.
There was this contact rolling around inside the case:


It came off the disc in the overload. Do you think it wasn't welded properly or it somehow actually got hot enough to melt the welds? It doesn't look like it got that hot.

EBEBRATT-Ed

I don't know but I have had problems with the cheap little "dorm" refrigerators when the compressor won't start it always the cheezy little ptc starter that quits

mattmia2

the original overload and start relay made it through over 30 years of short cycling

ratio

Why do you say it was short cycling?

mattmia2

@ratio the cold control was positioned from the factory such that the cold air vents in the top of the partition between the freezer and refrigerator would blow cold air from the evaporator on to it. This would cause it to sense the air from the evaporator rather than the general compartment temp, it would shut the compressor off, the cold control would reach the temp of the air in the compartment in a minute or 2, especially if you opened the door at that point, the system wouldn't have equalized yet, the cold control would turn on the compressor and the overload would trip out, the overload would cool off in a couple minutes and the compressor would start. I thought it was the top shelves being to high, but I moved them down and it did the same thing. There is a little hole in the back of the plastic cover over the cold control that allows the cold air to blow directly in to the cover. I plugged up that hole after the original overload became intermittent about a year and a half ago and the short cycling stopped.

ratio

Way to go, factory! Factory screwups are hard to find sometimes.

mattmia2

I'm curious about how it was supposed to work. The hole looked like it was intended to be there for the cold control to sense the compartment temp. Was there some baffles the delivery people threw out or the factory didn't install? Was there a design change in the partition? Did they just put parts together that were designed to be in different designs when they designed that model?